577000

Appears in sequences

• Triangular array read by rows. T(n,k) is the number of labeled digraphs on [n] with exactly k isolated strongly connected components, n>=0, 0<=k<=n.at n=16A362226
• G.f. A(x) satisfies A(x) = 1 / (1 - x - x * A(x^3)).at n=17A367659