

A186724


Number of connected regular graphs with n nodes and girth at least 4.


19



1, 1, 1, 0, 1, 1, 2, 1, 4, 1, 10, 3, 37, 32, 340, 1608, 18020, 193907, 2867725, 32674058, 1581632114, 6705889824
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OFFSET

0,7


LINKS



FORMULA

a(n) = sum of the nth row of A186714.


CROSSREFS

Regular graphs, of any degree, with girth at least 4: this sequence (connected), A185214 (disconnected), A185314 (not necessarily connected).


KEYWORD

nonn,hard,more


AUTHOR



STATUS

approved



