A076434 Number of weakly regular simple graphs on n nodes.

0, 0, 0, 0, 0, 2, 4, 16, 21, 168, 544, 18992, 389451, 50314864

Offset

1,6

Links

Table of n, a(n) for n=1..14.

Eric Weisstein's World of Mathematics, Weakly Regular Graph

Formula

a(n) = A005176(n) - A076435(n). - Andrew Howroyd, Sep 03 2019

Crossrefs

Cf. A005176 (regular simple graphs on n nodes).

Cf. A294405 (connected weakly regular graphs on n nodes).

Cf. A076435 (strongly regular simple graphs on n nodes).

Sequence in context: A045521 A338766 A242205 * A192150 A049441 A253143

Adjacent sequences: A076431 A076432 A076433 * A076435 A076436 A076437

Keyword

nonn,more

Author

Eric W. Weisstein, Oct 11 2002

Extensions

a(10) from Eric W. Weisstein, Oct 30 2017

a(11)-a(14) from Sean A. Irvine, Apr 04 2025

Status

approved