A185316 Number of, not necessarily connected, regular simple graphs on n vertices with girth at least 6.

1, 1, 2, 1, 2, 1, 3, 2, 3, 2, 3, 2, 4, 3, 6, 4, 7, 5, 13, 7, 42, 10, 398, 13, 7592, 18, 181251, 25, 4624534, 33, 122090591, 45, 3328930034, 61, 93990693977, 106

Offset

0,3

Links

Table of n, a(n) for n=0..35.

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

Formula

a(n) = A186726(n) + A185216(n).

Crossrefs

Not necessarily connected regular simple graphs with girth at least g: A005176 (g=3), A185314 (g=4), A185315 (g=5), this sequence (g=6), A185317 (g=7), A185318 (g=8), A185319 (g=9).

Sequence in context: A354713 A265893 A191372 * A053279 A046800 A338718

Adjacent sequences: A185313 A185314 A185315 * A185317 A185318 A185319

Keyword

nonn,more,hard

Author

Jason Kimberley, Dec 12 2012

Status

approved