21568

Appears in sequences

• a(n) = A000695(A014486(n)).at n=21A083931
• Molien series for symmetrized weight enumerators of self-dual codes over GF(4) + GF(4)u with u^2 = 0.at n=44A092549
• a(n) = smallest number greater than a(n-1) having a largest proper divisor that is greater than and coprime to a(n-1); a(1) = 1.at n=37A098144
• Number of degeneracies on the sets of N ordinary trees with p vertices.at n=10A121221
• a(n) = ((1+sqrt(13))^n + (1-sqrt(13))^n)/2.at n=7A125816
• Sequence arising from the factorization of F(n)= A091914(n-1) and L(n)= A127262. F(0)=0, F(1)=1, F(n)=2*F(n-1)+12*F(n-2), L(0)=2, L(1)=2, L(n)=2*L(n-1)+12*L(n-2).at n=6A127609
• Number of permutations of 1..n with the permutation and its inverse having a different number of maxima.at n=7A180390
• Theta series of direct sum of 2 copies of 4-dimensional lattice QQF.4.i.at n=14A212817
• Principal diagonal of the convolution array A213847.at n=15A213848
• Number of partitions p = [x(1), ..., x(k)], where x(1) >= x(2) >= ... >= x(k), of n such that max(x(i) - x(i-1)) <= number of parts of p.at n=38A241829
• Triangle read by rows: T(n, k) = (k + 1)*T(n-1, k) + Sum_{j=k..n-1} T(n-1, j) for k < n, T(n, n) = 1. T(n, k) for n >= 0 and 0 <= k <= n.at n=48A242431
• p-INVERT of (1,0,0,1,0,0,0,0,0,0,...), where p(S) = 1 - S^2.at n=34A292402
• Expansion of Product_{k>=0} (1 + x^(4^k))^(4^(k+1)).at n=21A321355
• Expansion of Product_{k>=0} (1 + x^(4^k))^(4^(k+1)).at n=23A321355
• a(n) = n^4 + 28*n^3 + 252*n^2 + 784*n + 448.at n=6A346514
• Numbers k such that the concatenation 1,2,3,... up to (k-1) is one less than a multiple of k.at n=47A358610
• a(n) is the smallest centered n-gonal number with exactly n prime factors (counted with multiplicity).at n=4A358926