

A184983


Number of connected 8regular simple graphs on n vertices with girth exactly 3.


9



0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 6, 94, 10786, 3459386, 1470293676, 733351105934
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OFFSET

0,12


LINKS



FORMULA



EXAMPLE

a(0)=0 because even though the null graph (on zero vertices) is vacuously 8regular and connected, since it is acyclic, it has infinite girth.
The a(9)=1 complete graph on 9 vertices is 8regular; it has 36 edges and 84 triangles.


MATHEMATICA

A[s_Integer] := With[{s6 = StringPadLeft[ToString[s], 6, "0"]}, Cases[ Import["https://oeis.org/A" <> s6 <> "/b" <> s6 <> ".txt", "Table"], {_, _}][[All, 2]]];


CROSSREFS

Connected 8regular simple graphs with girth at least g: A014378 (g=3), A181154 (g=4).
Connected 8regular simple graphs with girth exactly g: this sequence (g=3).


KEYWORD

nonn,hard,more


AUTHOR



STATUS

approved



