27990

Appears in sequences

• Number of connected 2-element antichains on a labeled n-set.at n=10A094033
• Triangle T : T(n,k)= binomial(n,k)*A000957(n+1-k).at n=57A171616
• Worpitzky(n, k)*Harmonic(k), triangle read by rows.at n=47A176276
• Number of n-node rooted identity trees with thinning limbs and root outdegree (branching factor) 4.at n=13A245123
• Triangle read by rows: T(n, k) = (k+1)*S2(n+1, k+1), for n >= k >= 0, and S2 = A048993 (Stirling2).at n=47A321331