116725

Appears in sequences

• Vampire numbers (definition 2): numbers n with an even number of digits which have a factorization n = i*j where i and j have the same number of digits and the multiset of the digits of n coincides with the multiset of the digits of i and j.at n=15A014575
• Vampire numbers permutations of whose digits are other vampire numbers.at n=6A167266
• Coefficient of x in the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=20A192957
• G.f. satisfies: A(x) = exp( Sum_{n>=1} x^n/n * Sum_{k=0..n} C(n,k)*A(x^(n+k)) ).at n=10A199102
• a(n) = (n + 1)*(2*n + 1)*(4*n + 9)/3.at n=34A269342