A186747 Number of connected regular simple graphs on n vertices with girth exactly 7.

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 3, 0, 21, 0, 545, 0, 30368, 0, 1782839, 0, 95079080, 0, 4686063107, 0

Offset

0,27

Links

Table of n, a(n) for n=0..39.

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

Formula

a(n) = A186727(n) - A186728(n).

Crossrefs

Sequence in context: A009353 A215583 A215678 * A083289 A108196 A370015

Adjacent sequences: A186744 A186745 A186746 * A186748 A186749 A186750

Keyword

nonn,more,hard

Author

Jason Kimberley, Apr 03 2012

Status

approved