A186744 - OEIS

%I #4 Apr 03 2012 11:56:37

%S 0,0,0,0,1,0,1,0,3,0,8,2,34,31,330,1607,17970,193906,2867269,32674056,

%T 1581626328,6705889815

%N Number of connected regular simple graphs on n vertices with girth exactly 4.

%H Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/C_k-reg_girth_eq_g_index">Index of sequences counting connected k-regular simple graphs with girth exactly g</a>

%F a(n) = A186724(n) - A186725(n).

%K nonn,more,hard

%O 0,9

%A _Jason Kimberley_, Apr 03 2012