A186746 Number of connected regular simple graphs on n vertices with girth exactly 6.

0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 5, 0, 32, 0, 385, 0, 7573, 0, 181225, 0, 4624481, 0, 122090002, 0, 3328899605, 0, 93988911027, 25, 2754128020324, 13504

Offset

0,19

Links

Table of n, a(n) for n=0..37.

Jason Kimberley, Index of sequences counting connected k-regular simple graphs with girth exactly g

Formula

a(n) = A186726(n) - A186727(n).

Crossrefs

Cf. A186726, A186727.

Sequence in context: A279548 A279701 A279604 * A208928 A348209 A368768

Adjacent sequences: A186743 A186744 A186745 * A186747 A186748 A186749

Keyword

nonn,more,hard

Author

Jason Kimberley, Apr 03 2012

Extensions

a(36)-a(37) from Jinyuan Wang, Mar 02 2020

Status

approved