42651

Appears in sequences

• Number T(n,k) of set partitions of [n] where each subset is again partitioned into k nonempty subsets; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=60A324162
• Number of set partitions of [2n] where each subset is again partitioned into n nonempty subsets.at n=5A324241
• Number of set partitions of [n] where each subset is again partitioned into five nonempty subsets.at n=10A327506
• Expansion of e.g.f. -log( 1 - (exp(x) - 1)^5 / 5! ).at n=5A346955
• Odd numbers k such that k and k+2 both have at least two divisors with the same value of the Euler totient function (A000010).at n=2A373527
• G.f. A(x) = exp( Sum_{n>=1} (n^2 - A384819(n))*x^n/n ) where A384819(k) < k for k >= 1 such that A(x) is a power series with integral coefficients.at n=22A384820