A185317 - OEIS

A185317

Number of, not necessarily connected, regular simple graphs on n vertices with girth at least 7.

1, 1, 2, 1, 2, 1, 2, 2, 3, 2, 3, 2, 3, 2, 4, 3, 5, 4, 6, 5, 7, 7, 9, 9, 13, 12, 18, 16, 41, 21, 572, 28, 30402, 37, 1782884, 49, 95079141, 64, 4686063195, 84

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

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

Jason Kimberley, Index of sequences counting not necessarily connected k-regular simple graphs with girth at least g

FORMULA

a(n) = A186727(n) + A185217(n).

CROSSREFS

Not necessarily connected regular simple graphs with girth at least g: A005176 (g=3), A185314 (g=4), A185315 (g=5), A185316 (g=6), this sequence (g=7), A185318 (g=8), A185319 (g=9).

Sequence in context: A257694 A281543 A287476 * A373606 A008682 A112224

Adjacent sequences: A185314 A185315 A185316 * A185318 A185319 A185320

KEYWORD

nonn,more,hard

AUTHOR

Jason Kimberley, Dec 12 2012

STATUS

approved