98253

Appears in sequences

• Set partitions without singletons: number of partitions of an n-set into blocks of size > 1. Also number of cyclically spaced (or feasible) partitions.at n=11A000296
• Let sum(k>=0, k^n/(2*k+1)!) = (x(n)*e + y(n)/e)/z(n), where x(n) and z(n) are >0, then a(n)=x(n).at n=10A080093
• T(n,k) counts the set partitions of n containing k-1 blocks of length 1.at n=45A086659
• Number of four-prime Carmichael numbers less than 10^n.at n=20A174612
• Triangular array read by rows: T(n,k) is the number of set partitions of {1,2,...,n} in which the shortest block has length k (1 <= k <= n).at n=45A178979
• Triangle read by rows, arising in enumeration of permutations by cyclic peaks, cycles and fixed points.at n=31A216963
• Triangle read by rows, T(n,k) = T(n-1,k-1) + k*T(n-1,k) + (k+1)*T(n-1,k+1), T(0,0) = 1, n >= 0, k >= 0.at n=56A217537
• Triangle of partitions of an n-set into boxes of size >= m.at n=56A282988
• Number T(n,k) of set partitions of [n] such that at least one of the block sizes is k or k=0; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=56A327884