A308556 Number of (not necessarily connected) ungraceful graphs on n nodes.

0, 1, 2, 4, 12, 30, 85, 300, 1998, 32320

Offset

1,3

Links

Table of n, a(n) for n=1..10.

Eric Weisstein's World of Mathematics, Graceful Graph

Formula

a(n) = A000088(n) - A308548(n). - Pontus von Brömssen, Dec 29 2024

Crossrefs

Cf. A000088, A308548, A308557 (connected ungraceful graphs).

Sequence in context: A059412 A079472 A366590 * A148186 A006948 A148187

Adjacent sequences: A308553 A308554 A308555 * A308557 A308558 A308559

Keyword

nonn,more,hard

Author

Eric W. Weisstein, Jun 07 2019

Extensions

a(8) from Eric W. Weisstein, Aug 16 2019

a(9) from Eric W. Weisstein, Nov 11 2025

a(10) from Eric W. Weisstein, Feb 27 2026

Status

approved