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A185354
Number of not necessarily connected 5-regular simple graphs on 2n vertices with girth at least 4.
9
1, 0, 0, 0, 0, 1, 1, 7, 388, 406824, 1125022326, 3813549359275
OFFSET
0,8
FORMULA
This sequence is the Euler transformation of A058275.
a(n) = A058275(n) + A185254(n).
MATHEMATICA
A058275 = Cases[Import["https://oeis.org/A058275/b058275.txt", "Table"], {_, _}][[All, 2]];
(* EulerTransform is defined in A005195 *)
EulerTransform[Rest @ A058275] (* Jean-François Alcover, Dec 04 2019, updated Mar 18 2020 *)
CROSSREFS
5-regular simple graphs on 2n vertices with girth at least 4: A058275 (connected), A185254 (disconnected), this sequence (not necessarily connected).
Not necessarily connected k-regular simple graphs with girth at least 4: A185314 (any k), A185304 (triangle); specified degree k: A008484 (k=2), A185334 (k=3), A185344 (k=4), this sequence (k=5), A185364 (k=6).
Sequence in context: A293459 A058275 A184954 * A222893 A009712 A128793
KEYWORD
hard,nonn,more
AUTHOR
Jason Kimberley, Nov 04 2011
STATUS
approved