A140981 Number of graphs with n vertices that have an even determinant for the adjacency matrix.

1, 1, 4, 7, 34, 109, 1044, 8303, 274668, 7451736, 1018997864

Offset

1,3

Links

Table of n, a(n) for n=1..11.

Formula

a(n) = A000088(n) - A141040(n/2) for n even, a(n) = A000088(n) for n odd.

Crossrefs

Cf. A000088, A103869, A141040.

Sequence in context: A149090 A103059 A123809 * A283819 A124624 A209480

Adjacent sequences: A140978 A140979 A140980 * A140982 A140983 A140984

Keyword

more,nonn

Author

Tanya Khovanova, Aug 18 2008

Extensions

a(8)-a(10) from Andrew Howroyd, Nov 04 2017

a(11) from A000088 added by Max Alekseyev, Feb 20 2024

Status

approved