25471105

Appears in sequences

• Number of isomorphism classes of n-fold coverings of a connected graph with Betti number 3.at n=6A152612
• Array read by antidiagonals: T(n,k) is the number of isomorphism classes of n-fold coverings of a connected graph with Betti number k (1 <= n, 0 <= k).at n=48A160449