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A184953
Number of connected 5-regular (or quintic) simple graphs on 2n vertices with girth exactly 3.
12
0, 0, 0, 1, 3, 59, 7847, 3459376, 2585136287, 2807104844073
OFFSET
0,5
LINKS
Eric Weisstein's World of Mathematics, Girth.
Eric Weisstein's World of Mathematics, Quintic Graph.
FORMULA
a(n) = A006821(n) - A058275(n).
CROSSREFS
Connected k-regular simple graphs with girth exactly 3: A006923 (k=3), A184943 (k=4), this sequence (k=5), A184963 (k=6), A184973 (k=7), A184983 (k=8), A184993 (k=9).
Connected 5-regular simple graphs with girth at least g: A006821 (g=3), A058275 (g=4).
Connected 5-regular simple graphs with girth exactly g: this sequence (g=3), A184954 (g=4), A184955 (g=5).
Sequence in context: A305597 A369949 A062629 * A185153 A215609 A360837
KEYWORD
nonn,more,hard
AUTHOR
Jason Kimberley, Feb 27 2011
STATUS
approved