A236525 Number of simple non-bipartite graphs on n nodes.

0, 0, 1, 4, 21, 121, 956, 12043, 273549, 11999689, 1018965561, 165090921457, 50502028840240, 29054155623249635, 31426485969192461828, 64001015704512693244004, 245935864153532444460997784, 1787577725145611678835828915650, 24637809253125004523074706811821299

Offset

1,4

Links

Andrew Howroyd, Table of n, a(n) for n = 1..50

Formula

a(n) = A000088(n) - A033995(n).

Example

a(3) = 1 since the only non-bipartite graph on 3 vertices is the triangle.

Prog

(Sage) def a(n): return len([G for G in graphs(n) if not G.is_bipartite()])

Crossrefs

Cf. A000088, A033995.

Sequence in context: A101810 A371774 A274969 * A277292 A001888 A103769

Adjacent sequences: A236522 A236523 A236524 * A236526 A236527 A236528

Keyword

nonn

Author

Jernej Azarija, Jan 29 2014

Extensions

More terms from Joerg Arndt, Feb 01 2014

Status

approved