33832

Appears in sequences

• Number of subsets of the first n numbers having a common divisor greater than 1.at n=29A109511
• Number of functions f:{1,2,...,n}->{1,2,...,n} whose cycle lengths are <= 2.at n=6A209319
• Number A(n,k) of endofunctions on [n] whose cycle lengths are divisors of k; square array A(n,k), n>=0, k>=0, read by antidiagonals.at n=42A246522
• Number of strong triangulations of a disk with n nodes.at n=7A341919
• G.f. satisfies A(x) = 1/(1-x) + x^2*(1-x)*A(x)^3.at n=13A364593