496680

Appears in sequences

• Irregular array, read by rows: T(n,k) is the number of labeled acyclic digraphs with n nodes and k arcs (n >= 0, 0 <= k <= n*(n-1)/2).at n=33A081064
• Number of consistent sets of 7 irreflexive binary order relationships over n objects.at n=1A147872
• a(n,k) equals (1/n!) multiplied by the count of permutations with cycle length k in all products u v u^-1 v^-1 over all permutations u and v of length n.at n=61A191716