21816

Appears in sequences

• Expansion of ( Sum_{n = -infinity..infinity} x^(n^2) )^(-12).at n=4A004413
• Numbers k such that (273*2^k+1)^2-2 is prime.at n=29A100914
• Numbers with at least two 3s in their prime signature.at n=52A109399
• a(n) = 12*a(n-1) - 30*a(n-2) with a(0)=1 and a(1)=6.at n=5A145301
• 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), (0, 1, -1), (1, 0, 1)}.at n=12A148086
• A triangle of matrix polynomials: m(n)=antisymmeticmatix(n).Transpose[antisymmeticmatix(n)].at n=49A158335
• Numbers of the form p^3*q^3*r where p, q, and r are prime.at n=33A179688
• Row sums of triangle A182701.at n=17A182705
• Irregular triangle read by rows: coefficients in order of decreasing exponents of polynomials P_g(x) related to Hultman numbers.at n=37A185259
• Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=6A240256
• T(n,k)=Number of nXk 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=34A240260
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 438", based on the 5-celled von Neumann neighborhood.at n=7A272218
• Expansion of (1 + 2*x)/(1 - 6*x + 6*x^2).at n=6A276265
• Number of 10-element subsets of [n+10] having an even sum.at n=8A282078
• Number of n-element subsets of [n+8] having an even sum.at n=10A282084
• Numbers k such that A284644(k) = A284644(k-1) = A284644(k-2) = A284644(k-3).at n=9A287118
• Expansion of 1/theta_4(q)^12 in powers of q = exp(Pi i t).at n=4A319554
• Triangle read by rows: T(n,k) is the number of non-crossing set partitions of {1..4n} into n sets of 4 with k of the sets being a contiguous set of elements.at n=42A334062
• Number of length-2n binary strings of the form xxyy.at n=10A347582
• a(n) is the smallest number that has exactly n divisors that are cyclops numbers (A134808).at n=8A357033