250240

Appears in sequences

• Birooted graphs: number of unlabeled graphs with n nodes rooted at 2 indistinguishable roots.at n=7A303829
• Triangle read by rows: T(n,k) is the number of graphs with loops on n unlabeled vertices with k loops.at n=38A361404
• Triangle read by rows: T(n,k) is the number of graphs with loops on n unlabeled vertices with k loops.at n=42A361404