This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A185244 #24 May 01 2014 02:37:02 %S A185244 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,2,2,15,35,247,1692,17409,197924, %T A185244 2492824,33117880,461597957,6709514218,101153412903,1597440868898 %N A185244 Number of disconnected 4-regular simple graphs on n vertices with girth at least 4. %H A185244 Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/D_k-reg_girth_ge_g_index">Index of sequences counting disconnected k-regular simple graphs with girth at least g</a> %F A185244 a(n) = A185344(n) - A033886(n) = Euler_transformation(A033886)(n) - A033886(n). %F A185244 a(n) = A185044(n) + A185245(n). %Y A185244 4-regular simple graphs with girth at least 4: A033886 (connected), this sequence (disconnected), A185344 (not necessarily connected). %Y A185244 Disconnected 4-regular simple graphs with girth at least g: A033483 (g=3), this sequence (g=4), A185245 (g=5), A185246 (g=6). %Y A185244 Disconnected k-regular simple graphs with girth at least 4: A185214 (any k), A185204 (triangle); specified degree k: A185224 (k=2), A185234 (k=3), this sequence (k=4), A185254 (k=5), A185264 (k=6), A185274 (k=7), A185284 (k=8), A185294 (k=9). %K A185244 nonn,more,hard %O A185244 0,19 %A A185244 _Jason Kimberley_, Feb 22 2011 %E A185244 a(31) appended by the author once A033886(23) was known, Nov 03 2011 %E A185244 a(31) corrected by the author, Jan 05 2013