A186745 Number of connected regular simple graphs on n vertices with girth exactly 5.

0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 2, 0, 8, 0, 48, 0, 450, 1, 5753, 8, 90684, 3917, 1736764, 4131991, 163457964, 4018022149, 119021971348

Offset

0,13

Links

Table of n, a(n) for n=0..28.

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

Formula

a(n) = A186725(n) - A186726(n).

Crossrefs

Sequence in context: A347596 A211163 A239275 * A109573 A305809 A349139

Adjacent sequences: A186742 A186743 A186744 * A186746 A186747 A186748

Keyword

nonn,more,hard

Author

Jason Kimberley, Apr 03 2012

Extensions

a(26) corrected by the author, due to correction of A186725, May 19 2017

Status

approved