%I
%S 0,0,0,0,1,0,1,0,4,1,8,3,37,33,335,1610,17985,193911,2867313,32674066,
%T 1581626531,6705889862
%N Number of, not necessarily connected, regular simple graphs on n vertices with girth exactly 4.
%H Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/E_kreg_girth_eq_g_index">Index of sequences counting not necessarily connected kregular simple graphs with girth exactly g</a>
%F a(n) = A186744(n) + A210714(n).
%F a(n) = A185314(n)  A185315(n).
%Y Not necessarily connected kregular simple graphs girth exactly 4: this sequence (any k), A185644 (triangle); fixed k: A026797 (k=2), A185134 (k=3), A185144 (k=4).
%Y Not necessarily connected regular simple graphs girth exactly g: A198313 (g=3), this sequence (g=4), A198315 (g=5), A198316 (g=6), A198317 (g=7), A198318 (g=8).
%K nonn,more,hard
%O 0,9
%A _Jason Kimberley_, Dec 12 2012
%E a(10) corrected from 9 to 8 by _Jason Kimberley_, Feb 22 2013
