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A185315
Number of, not necessarily connected, regular simple graphs on n vertices with girth at least 5.
11
1, 1, 2, 1, 2, 2, 3, 2, 3, 2, 5, 3, 7, 4, 15, 6, 57, 8, 466, 12, 5801, 24, 91091, 3939, 1744378, 4132022, 163639295, 4018022192, 119026596500
OFFSET
0,3
FORMULA
a(n) = A186725(n) + A185215(n).
CROSSREFS
Not necessarily connected k-regular simple graphs with girth at least 5: this sequence (any k), A185305 (triangle); specified degree k: A185325 (k=2), A185335 (k=3).
Not necessarily connected regular simple graphs with girth at least g: A005176 (g=3), A185314 (g=4), this sequence (g=5), A185316 (g=6), A185317 (g=7), A185318 (g=8), A185319 (g=9).
Sequence in context: A143966 A260617 A178695 * A232548 A029363 A304708
KEYWORD
nonn,more,hard
AUTHOR
Jason Kimberley, Dec 12 2012
STATUS
approved