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DECAGONAL NUMBER

  • Decagonal number
  • Figurate number representing a decagon

    In mathematics, a decagonal number is a figurate number that extends the concept of triangular and square numbers to the decagon (a ten-sided polygon)

    Decagonal number

    Decagonal_number

  • Centered decagonal number
  • Centered figurate number that represents a decagon with a dot in the center

    A centered decagonal number is a centered figurate number that represents a decagon with a dot in the center and all other dots surrounding the center

    Centered decagonal number

    Centered decagonal number

    Centered_decagonal_number

  • 1000 (number)
  • Natural number

    a centered pentagonal number, and a centered decagonal number. 1056 = 25 × 3 × 11. It is a pronic number. 1060 = 22 × 5 × 53. It is the sum of the first

    1000 (number)

    1000_(number)

  • 4000 (number)
  • Natural number

    (four thousand) is the natural number following 3999 and preceding 4001. It is a decagonal number. 4005 – triangular number 4007 – safe prime 4010 – magic

    4000 (number)

    4000_(number)

  • 2000 (number)
  • Natural number

    Mersenne number that is composite for a prime exponent. It is a super-Poulet number, a Woodall number, a decagonal number, and a centered octahedral number. 2053

    2000 (number)

    2000_(number)

  • 5000 (number)
  • Natural number

    Kaprekar number, 5051 – Sophie Germain prime 5059 – super-prime 5076 – decagonal number 5081 – Sophie Germain prime 5087 – safe prime 5099 – safe prime 5107

    5000 (number)

    5000_(number)

  • 31 (number)
  • Natural number

    as 25 - 1. 31 is a centered triangular number, a centered pentagonal number, and a centered decagonal number. 31 equal temperament is a popular microtonal

    31 (number)

    31_(number)

  • 3000 (number)
  • Natural number

    octagonal number, dodecagonal number 3037 – star number, cousin prime with 3041 3046 – centered heptagonal number 3052 – decagonal number 3059 – centered

    3000 (number)

    3000_(number)

  • 7000 (number)
  • Natural number

    heptagonal number 7247 – safe prime 7260 – triangular number 7267 – decagonal number 7272 – Kaprekar number 7283 – super-prime 7291 – nonagonal number 7310

    7000 (number)

    7000_(number)

  • 900 (number)
  • Natural number

    Since 913 is a semiprime, 911 is a Chen prime. It is also a centered decagonal number. There are 911 inverse semigroups of order 7. 911 is obtained by concatenating

    900 (number)

    900_(number)

  • 600 (number)
  • Natural number

    is a decagonal number and a zero of the Mertens function. 638 = 2 × 11 × 29. It is a sphenic number, a nontotient, a centered heptagonal number, and the

    600 (number)

    600_(number)

  • 6000 (number)
  • Natural number

    centered octagonal number 6250 – Leyland number 6263 – Sophie Germain prime, balanced prime 6269 – Sophie Germain prime 6280 – decagonal number 6311 – super-prime

    6000 (number)

    6000_(number)

  • 9000 (number)
  • Natural number

    octagonal number 9029 – Sophie Germain prime 9041 – super-prime 9045 – triangular number 9059 – Sophie Germain prime 9072 – decagonal number 9077 – Markov

    9000 (number)

    9000_(number)

  • 85 (number)
  • Natural number

    23,1,0). an octahedral number. a centered triangular number. a centered square number. a decagonal number. the smallest number that can be expressed as

    85 (number)

    85_(number)

  • 52 (number)
  • Natural number

    it is not equal to x − φ(x) for any x . 52 is a decagonal number and a vertically symmetrical number. "Bell, or exponential numbers". The On-Line Encyclopedia

    52 (number)

    52_(number)

  • 8000 (number)
  • Natural number

    nonagonal number, centered octagonal number 8287 – super-prime 8321 – super-Poulet number 8326 – decagonal number 8345 – smallest pandigital number in base

    8000 (number)

    8000_(number)

  • 700 (number)
  • Natural number

    number and the 38th triangular number. 742 = 2 × 7 × 53. It is a sphenic number, a decagonal number, an icosahedral number, and a lazy caterer number

    700 (number)

    700_(number)

  • 300 (number)
  • Natural number

    strictly non-palindromic number. 361 = 192. 361 is a centered triangular number, a centered octagonal number, a centered decagonal number and a member of the

    300 (number)

    300_(number)

  • 151 (number)
  • Natural number

    twin prime. 151 is also a palindromic prime, a centered decagonal number, and a lucky number. 151 appears in the Padovan sequence, preceded by the terms

    151 (number)

    151_(number)

  • 800 (number)
  • Natural number

    number and a nontotient. There are 854 unlabeled planar trees with 11 nodes. 855 = 32 × 5 × 19. It is a decagonal number and a centered cube number.

    800 (number)

    800_(number)

  • 61 (number)
  • Natural number

    {\displaystyle 5^{2}+6^{2}} . It is also a centered decagonal number, and a centered hexagonal number. 61 is the fourth cuban prime of the form p = x 3

    61 (number)

    61_(number)

  • 175 (number)
  • Natural number

    figurate number for a rhombic dodecahedron, the difference of two consecutive fourth powers: 175 = 44 − 34. It is also a decagonal number and a decagonal pyramid

    175 (number)

    175_(number)

  • 232 (number)
  • Natural number

    is the natural number following 231 and preceding 233. 232 is both a central polygonal number, a decagonal number, and a cake number. It is both It is

    232 (number)

    232_(number)

  • 126 (number)
  • Natural number

    the only such Granville number. 126 is a pentagonal pyramidal number and a decagonal number. 126 is also the different number of ways to partition a decagon

    126 (number)

    126_(number)

  • 12,000 (number)
  • Natural number

    which has 48 divisors. It is also a regular number, a 3 times decagonal number, a number in base -3, and a number of the Hamiltonian cycles in the rook graph

    12,000 (number)

    12,000_(number)

  • Decagon
  • Shape with ten sides

    The number of sides in the Petrie polygon is equal to the Coxeter number, h, for each symmetry family. Decagonal number and centered decagonal number, figurate

    Decagon

    Decagon

    Decagon

  • 500 (number)
  • Natural number

    22 × 33 × 5. It is a largely composite number, an untouchable number, a heptagonal number, and a decagonal number. It is the sum of a pair of twin primes

    500 (number)

    500_(number)

  • Perfect number
  • Number equal to the sum of its proper divisors

    In number theory, a perfect number is a positive integer that is equal to the sum of its positive proper divisors, that is, divisors excluding the number

    Perfect number

    Perfect number

    Perfect_number

  • 100,000
  • Natural number

    prime factor of F12 115,975 = Bell number 116,281 = 3412, square number, centered decagonal number, 18-gonal number 117,067 = first vampire prime 117,649

    100,000

    100,000

  • 400 (number)
  • Natural number

    It is a Wedderburn–Etherington number and a centered decagonal number. It is the smallest number whose reciprocal has period 10. 452 = 22 × 113. There

    400 (number)

    400_(number)

  • 281 (number)
  • Natural number

    Chen prime, Eisenstein prime with no imaginary part, and a centered decagonal number. 281 is the smallest prime p such that the decimal period length of

    281 (number)

    281_(number)

  • Triangular number
  • Figurate number

    The triangular lattice representing the n {\displaystyle n} th triangular number contains n {\displaystyle n} rows: the first row contains one point, the

    Triangular number

    Triangular number

    Triangular_number

  • 297 (number)
  • Natural number

    partitions of 17. 297 is a decagonal number which applies the properties of triangular numbers to decagons. 297 is a Kaprekar number which means that it can

    297 (number)

    297_(number)

  • Natural number
  • Number used for counting

    natural-number results: subtracting a larger natural number from a smaller one results in a negative number and dividing one natural number by another

    Natural number

    Natural number

    Natural_number

  • 1105 (number)
  • Natural number

    introducing this concept. It is also a Fermat pseudoprime, a decagonal number, and a centered square number. It is a member of the Moser–de Bruijn sequence of sums

    1105 (number)

    1105_(number)

  • Composite number
  • Integer having a non-trivial divisor

    A composite number is a positive integer that can be formed by multiplying two smaller positive integers. Accordingly, it is a positive integer that has

    Composite number

    Composite number

    Composite_number

  • Prime number
  • Number divisible only by 1 and itself

    A prime number (or a prime) is a natural number greater than 1 that is not a product of two smaller natural numbers. A natural number greater than 1 that

    Prime number

    Prime number

    Prime_number

  • Square number
  • Product of an integer with itself

    In mathematics, a square number or perfect square is an integer that is the square of an integer; in other words, it is the product of some integer with

    Square number

    Square number

    Square_number

  • Sierpiński number
  • Odd number with specific properties

    In number theory, a Sierpiński number is an odd natural number k such that k × 2 n + 1 {\displaystyle k\times 2^{n}+1} is composite for all natural numbers

    Sierpiński number

    Sierpiński_number

  • List of recreational number theory topics
  • Polygonal number Triangular number Square number Pentagonal number Hexagonal number Heptagonal number Octagonal number Nonagonal number Decagonal number Centered

    List of recreational number theory topics

    List_of_recreational_number_theory_topics

  • Squared triangular number
  • Square of a triangular number

    In number theory, the sum of the first n cubes is the square of the nth triangular number. That is, 1 3 + 2 3 + 3 3 + ⋯ + n 3 = ( 1 + 2 + 3 + ⋯ + n ) 2

    Squared triangular number

    Squared triangular number

    Squared_triangular_number

  • Fibonacci sequence
  • Numbers obtained by adding the two previous ones

    month, the number of pairs of rabbits is equal to the number of mature pairs (that is, the number of pairs in month n – 2) plus the number of pairs alive

    Fibonacci sequence

    Fibonacci sequence

    Fibonacci_sequence

  • Tetrahedral number
  • Polyhedral number representing a tetrahedron

    A tetrahedral number, or triangular pyramidal number, is a figurate number that represents a pyramid with a triangular base and three sides, called a tetrahedron

    Tetrahedral number

    Tetrahedral number

    Tetrahedral_number

  • Congruent number
  • Area of a right triangle with rational-numbered sides

    In number theory, a congruent number is a positive integer that is the area of a right triangle with three rational number sides. A more general definition

    Congruent number

    Congruent number

    Congruent_number

  • Happy number
  • Numbers with a certain property involving recursive summation

    In number theory, a happy number is a number which eventually reaches 1 when the number is replaced by the sum of the square of each digit. For instance

    Happy number

    Happy number

    Happy_number

  • Kaprekar number
  • Base-dependent property of integers

    In mathematics, a natural number in a given number base is a p {\displaystyle p} -Kaprekar number if the representation of its square in that base can

    Kaprekar number

    Kaprekar_number

  • Catalan number
  • Recursive integer sequence

    they were previously discovered in the 1730s by Minggatu. The n-th Catalan number can be expressed directly in terms of the central binomial coefficients

    Catalan number

    Catalan number

    Catalan_number

  • 23 (number)
  • Natural number

    semiregular prisms (the triangular, pentagonal, hexagonal, octagonal, and decagonal prisms). 23 Coxeter groups of paracompact hyperbolic honeycombs in the

    23 (number)

    23_(number)

  • Lucky number
  • Integer filtered out using a sieve similar to that of Eratosthenes

    In number theory, a lucky number is a natural number in a set which is generated by a certain "sieve". This sieve is similar to the sieve of Eratosthenes

    Lucky number

    Lucky_number

  • Figurate number
  • Size of a geometric arrangement of points

    The term figurate number is used by different writers for members of different sets of numbers, generalizing from triangular numbers to different shapes

    Figurate number

    Figurate number

    Figurate_number

  • Centered hexagonal number
  • Number that represents a hexagon with a dot in the center

    mathematics and combinatorics, a centered hexagonal number, or centered hexagon number, is a centered figurate number that represents a hexagon with a dot in the

    Centered hexagonal number

    Centered hexagonal number

    Centered_hexagonal_number

  • Mersenne prime
  • Prime number of the form 2^n – 1

    mathematics, a Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number of the form Mn = 2n − 1 for some integer

    Mersenne prime

    Mersenne_prime

  • Cyclic number
  • Integer whose multiples are digit rotations

    A cyclic number is an integer for which cyclic permutations of the digits are successive integer multiples of the number. The most widely known is the

    Cyclic number

    Cyclic_number

  • Double Mersenne number
  • Number of form 2^(2^p-1)-1 with prime exponent

    In mathematics, a double Mersenne number is a Mersenne number of the form M M p = 2 2 p − 1 − 1 {\displaystyle M_{M_{p}}=2^{2^{p}-1}-1} where p {\displaystyle

    Double Mersenne number

    Double_Mersenne_number

  • Smooth number
  • Integer having only small prime factors

    In number theory, an n-smooth (or n-friable) number is an integer whose prime factors are all less than or equal to n. For example, a 7-smooth number is

    Smooth number

    Smooth_number

  • Abundant number
  • Number that is less than the sum of its proper divisors

    In number theory, an abundant number or excessive number is a positive integer for which the sum of its proper divisors is greater than the number. The

    Abundant number

    Abundant number

    Abundant_number

  • Friendly number
  • Two or more natural numbers with a common abundancy index

    In number theory, friendly numbers are two or more natural numbers with a common abundancy index, the ratio between the sum of divisors of a number and

    Friendly number

    Friendly_number

  • Hexagonal number
  • Type of figurate number

    A hexagonal number is a figurate number. The nth hexagonal number hn is the number of distinct dots in a pattern of dots consisting of the outlines of

    Hexagonal number

    Hexagonal number

    Hexagonal_number

  • Pell number
  • Number used to approximate the square root of 2

    starts with 0 and 1, and then each Pell number is the sum of twice the previous Pell number, plus the Pell number before that. The first few terms of the

    Pell number

    Pell number

    Pell_number

  • Lychrel number
  • Number, non-palindrome after repeated sum with reverse

    numbers exist? More unsolved problems in mathematics A Lychrel number is a natural number that cannot form a palindrome through the iterative process of

    Lychrel number

    Lychrel_number

  • Kaprekar's routine
  • Iterative algorithm on numbers

    In number theory, Kaprekar's routine is an iterative algorithm named after its inventor, Indian mathematician D. R. Kaprekar. Each iteration starts with

    Kaprekar's routine

    Kaprekar's_routine

  • Polygonal number
  • Type of figurate number

    In mathematics, a polygonal number is a number that counts dots arranged in the shape of a regular polygon. These are one type of 2-dimensional figurate

    Polygonal number

    Polygonal_number

  • Pronic number
  • Number, product of consecutive integers

    A pronic number is a number that is the product of two consecutive integers, that is, a number of the form n ( n + 1 ) {\displaystyle n(n+1)} . The study

    Pronic number

    Pronic_number

  • Keith number
  • Type of number introduced by Mike Keith

    mathematics, a Keith number or repfigit number (short for repetitive Fibonacci-like digit) is a natural number n {\displaystyle n} in a given number base b {\displaystyle

    Keith number

    Keith_number

  • Power of two
  • Two raised to an integer power

    A power of two is a number of the form 2n where n is an integer, that is, the result of exponentiation with the number two as the base and integer n as

    Power of two

    Power of two

    Power_of_two

  • Parasitic number
  • Number that when multiplied by another number moves its last digit to its front

    In mathematics, an n-parasitic number (in base 10) is a positive natural number which, when multiplied by n, results in movement of the last digit of its

    Parasitic number

    Parasitic_number

  • Cube (algebra)
  • Number raised to the third power

    algebra, the cube of a number n is its third power, that is, the result of multiplying three instances of n together. The cube of a number n is denoted n3,

    Cube (algebra)

    Cube (algebra)

    Cube_(algebra)

  • Regular number
  • Numbers that evenly divide powers of 60

    and have different names coming from their different areas of study. In number theory, these numbers are called 5-smooth, because they can be characterized

    Regular number

    Regular number

    Regular_number

  • Superior highly composite number
  • Class of natural numbers with many divisors

    In number theory, a superior highly composite number is a natural number which, in a particular rigorous sense, has many divisors. Particularly, it is

    Superior highly composite number

    Superior highly composite number

    Superior_highly_composite_number

  • Bell number
  • Count of the possible partitions of a set

    2,5,15,52,203,877,4140,\dots } (sequence A000110 in the OEIS). The Bell number B n {\displaystyle B_{n}} counts the different ways to partition a set that

    Bell number

    Bell number

    Bell_number

  • Delannoy number
  • Number of paths between grid corners, allowing diagonal steps

    In mathematics, a Delannoy number D {\displaystyle D} counts the paths from the southwest corner (0, 0) of a rectangular grid to the northeast corner (m

    Delannoy number

    Delannoy_number

  • Carmichael number
  • Composite number in number theory

    In number theory, a Carmichael number is a composite number ⁠ n {\displaystyle n} ⁠ which in modular arithmetic satisfies the congruence relation: b n

    Carmichael number

    Carmichael number

    Carmichael_number

  • Harshad number
  • Integer divisible by sum of its digits

    In recreational mathematics, a Harshad number (or Niven number) in a given number base is an integer that is divisible by the sum of its digits when written

    Harshad number

    Harshad_number

  • Jacobsthal number
  • Numbers in a type of Lucas sequence

    starts with 0 and 1, then each following number is found by adding the number before it to twice the number before that. The first Jacobsthal numbers

    Jacobsthal number

    Jacobsthal_number

  • Pentatope number
  • Number in the 5th cell of any row of Pascal's triangle

    In number theory, a pentatope number (or hypertetrahedral number or triangulo-triangular number) is a number in the fifth cell of any row of Pascal's

    Pentatope number

    Pentatope number

    Pentatope_number

  • Palindromic number
  • Number that remains the same when its digits are reversed

    A palindromic number (also known as a numeral palindrome or a numeric palindrome) is a number (such as 16361) that remains the same when its digits are

    Palindromic number

    Palindromic_number

  • Quasiperfect number
  • Numbers whose sum of divisors is twice the number plus 1

    unsolved problems in mathematics In mathematics, a quasiperfect number is a natural number n for which the sum of all its divisors (the sum-of-divisors function

    Quasiperfect number

    Quasiperfect_number

  • Nonagonal number
  • Type of figurate number

    A nonagonal number, or an enneagonal number, is a figurate number that extends the concept of triangular and square numbers to the nonagon (a nine-sided

    Nonagonal number

    Nonagonal_number

  • Vampire number
  • Type of composite number with an even number of digits

    recreational mathematics, a vampire number (or true vampire number) is a composite natural number with an even number of digits, that can be factored into

    Vampire number

    Vampire_number

  • 211 (number)
  • Natural number

    primes ( 67 + 71 + 73 {\displaystyle 67+71+73} ), a Chen prime, a centered decagonal prime, and a self prime. 211 is the smallest prime separated by 12 from

    211 (number)

    211_(number)

  • Power of 10
  • Ten raised to an integer power

    the number ten; in other words, ten multiplied by itself a certain number of times (when the power is a positive integer). By definition, the number one

    Power of 10

    Power of 10

    Power_of_10

  • Star number
  • Centered figurate number

    In mathematics, a star number is a centered figurate number, a centered hexagram (six-pointed star), such as the Star of David, or the board Chinese checkers

    Star number

    Star number

    Star_number

  • Lucas number
  • Infinite integer series where the next number is the sum of the two preceding it

    numbers two terms apart in the Fibonacci sequence results in the Lucas number in between. The first few Lucas numbers are 2, 1, 3, 4, 7, 11, 18, 29, 47

    Lucas number

    Lucas number

    Lucas_number

  • Narcissistic number
  • Concept in number theory

    In number theory, a narcissistic number (also known as a pluperfect digital invariant (PPDI), an Armstrong number (after Michael F. Armstrong) or a plus

    Narcissistic number

    Narcissistic_number

  • Deficient number
  • Number that is more than the sum of its proper divisors

    In number theory, a deficient number or defective number is a positive integer n for which the sum of divisors of n is less than 2n. Equivalently, it

    Deficient number

    Deficient number

    Deficient_number

  • Repdigit
  • Natural number with a decimal representation made of repeated instances of the same digit

    or sometimes monodigit is a natural number composed of repeated instances of the same digit in a positional number system (often implicitly decimal). The

    Repdigit

    Repdigit

  • Rough number
  • Positive integer with large prime factors

    A k-rough number, as defined by Finch in 2001 and 2003, is a positive integer whose prime factors are all greater than or equal to k. k-roughness has alternately

    Rough number

    Rough_number

  • Woodall number
  • Number of the form (n * 2^n) - 1

    number theory, a Woodall number (Wn) is any natural number of the form W n = n ⋅ 2 n − 1 {\displaystyle W_{n}=n\cdot 2^{n}-1} for some natural number

    Woodall number

    Woodall_number

  • Centered polygonal number
  • Class of series of figurate numbers, each having a central dot

    (OEIS: A060544), which include all even perfect numbers except 6, centered decagonal numbers 1, 11, 31, 61, 101, 151, 211, 281, 361, 451, 551, 661, ... (OEIS: A062786)

    Centered polygonal number

    Centered polygonal number

    Centered_polygonal_number

  • Cake number
  • Concept in combinatorics

    In mathematics, the cake number, denoted by Cn, is the maximum of the number of regions into which a 3-dimensional cube can be partitioned by exactly

    Cake number

    Cake number

    Cake_number

  • Pentagonal number
  • Figurate number

    A pentagonal number is a figurate number that extends the concept of triangular and square numbers to the pentagon, but, unlike the first two, the patterns

    Pentagonal number

    Pentagonal number

    Pentagonal_number

  • Repunit
  • Numbers that contain only the digit 1

    In recreational mathematics, a repunit is a number like 11, 111, or 1111 that contains only the digit 1 — a more specific type of repdigit. The term stands

    Repunit

    Repunit

  • Automorphic number
  • Number whose square ends in the same digits

    In mathematics, an automorphic number (sometimes referred to as a circular number) is a natural number in a given number base b {\displaystyle b} whose

    Automorphic number

    Automorphic_number

  • Exponentiation
  • Arithmetic operation

    b x {\displaystyle b^{x}} for any positive real number base b {\displaystyle b} and any real number exponent x {\displaystyle x} . A more involved definition

    Exponentiation

    Exponentiation

    Exponentiation

  • Square pyramidal number
  • Number of stacked spheres in a pyramid

    In mathematics, a pyramid number, or square pyramidal number, is a natural number that counts the stacked spheres in a pyramid with a square base. The

    Square pyramidal number

    Square pyramidal number

    Square_pyramidal_number

  • Fermat number
  • Positive integer of the form (2^(2^n))+1

    In mathematics, a Fermat number, named after Pierre de Fermat (1601–1665), the first known to have studied them, is a positive integer of the form: F n

    Fermat number

    Fermat_number

  • Semiprime
  • Product of two prime numbers

    In number theory, a semiprime is a natural number that is the product of exactly two prime numbers. The two primes in the product may equal each other

    Semiprime

    Semiprime

  • Stirling numbers of the second kind
  • Numbers parameterizing ways to partition a set

    particularly in combinatorics, a Stirling number of the second kind (or Stirling partition number) is the number of ways to partition a set of n objects

    Stirling numbers of the second kind

    Stirling numbers of the second kind

    Stirling_numbers_of_the_second_kind

  • Super-Poulet number
  • Type of Poulet number

    In number theory, a super-Poulet number is a Poulet number, or pseudoprime to base 2, whose every divisor d {\displaystyle d} divides 2 d − 2 {\displaystyle

    Super-Poulet number

    Super-Poulet_number

  • Polite number
  • Type of integer in number theory

    In number theory, a polite number is a positive integer that can be written as the sum of two or more consecutive positive integers. A positive integer

    Polite number

    Polite number

    Polite_number

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