1887284

Appears in sequences

• a(0), a(1), a(2), ... satisfy Sum_{k=0..n} a(k)*binomial(n,k) = 2^binomial(n,2), for n >= 0.at n=7A006129
• Triangular array read by rows T(n,k) is the number of simple labeled graphs on n nodes with exactly k isolated nodes, 0<=k<=n.at n=28A198261
• Regular triangle where T(n,k) is the number of labeled k-uniform hypergraphs spanning n vertices.at n=22A299471
• Triangle read by rows where T(n,k) is the number of labeled graphs with n vertices and k non-isolated vertices.at n=35A370319