13256
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 24870
- Proper Divisor Sum (Aliquot Sum)
- 11614
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6624
- Möbius Function
- 0
- Radical
- 3314
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 76
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 57.at n=33A031555
- Triangle of coefficients of generating function of 5-ary rooted trees of height at most n.at n=61A036607
- Number of 5-ary rooted trees with n nodes and height at most 4.at n=19A036615
- Number of semi-meanders of order n with 4 components.at n=7A046723
- Triangle of numbers of semi-meanders of order n with k components.at n=62A046726
- Triangle, read by rows, where the n-th row is the first n terms of the n-th self-convolution of the sequence formed by flattening this triangle.at n=35A086606
- Main diagonal of triangle A086606: the n-th term of the n-th self-convolution of the sequence formed by flattening triangle A086606.at n=7A086607
- Indices of primes in sequence defined by A(0) = 19, A(n) = 10*A(n-1) - 31 for n > 0.at n=21A102021
- Natural number transform of Aitken's triangle.at n=31A127740
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (1, -1, 1), (1, 0, -1), (1, 1, 0)}.at n=8A149384
- The number of ways one can flip seven consecutive tails (or heads) when flipping a coin n times.at n=18A151975
- Triangle T(n,k,p,q,j) = T(n-1,k,p,q,j) + T(n-1,k-1,p,q,j) + (p*j+q)*prime(j)*T(n-2,k-1,p,q,j) with T(2,k,p,q,j) = prime(j) and (p,q,j) = (0,1,2), read by rows.at n=49A153516
- Triangle T(n,k,p,q,j) = T(n-1,k,p,q,j) + T(n-1,k-1,p,q,j) + (p*j+q)*prime(j)*T(n-2,k-1,p,q,j) with T(2,k,p,q,j) = prime(j) and (p,q,j) = (0,1,2), read by rows.at n=50A153516
- Number of different equations that can be made by summing numbers from 1 to n and using every number not more than once.at n=12A161943
- a(1) = 2, a(n) = (n-th-even n^3) - (sum of previous terms).at n=24A181509
- 1/3 the number of n X 2 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.at n=6A185552
- 1/3 the number of n X 7 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.at n=1A185557
- T(n,k)=1/3 the number of nXk 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.at n=29A185559
- T(n,k)=1/3 the number of nXk 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.at n=34A185559
- Irregular triangle T(n,k), n>=1, 1<=k<=ceiling(n/2), read by rows: T(n,k) is the number of different ways to select k disjoint (nonempty) subsets from {1..n} with equal element sum.at n=43A196231