A353213 Number of simple unlabeled non-null graphs on <= n nodes.

1, 3, 7, 18, 52, 208, 1252, 13598, 288266, 12293434, 1031291298, 166122463890, 50668153831842, 29104823811067330, 31455590793615376098, 64032471295321173271026, 245999896624828253856990802, 1787823725042236528801735181650, 24639597076850046760911809226614418, 645514762392876691902925550299969363858

Offset: 1

Author

Eric W. Weisstein, Apr 30 2022

Keywords

• nonn

Comments

Also the number of (non-null) graph minors of the complete graph K_n.

Links

• Eric W. Weisstein, Table of n, a(n) for n = 1..87
• Eric Weisstein's World of Mathematics, Graph Minor
• Eric Weisstein's World of Mathematics, Simple Graph

Crossrefs

Cf. A000088 (number of simple graphs on n nodes).

Cf. A006897 (number of simple graphs on 0 to n nodes).

Formula

a(n) = A006897(n) - 1.

a(n) = Sum_{k=1..n} A000088(k).