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 A210717 #4 Dec 18 2012 11:14:44 %S A210717 0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,2,2,3,3,4,4,5,6,7,8,10,11, %T A210717 13,15,18,20,24,27,32,36,42,48,56,63,73,83,96,109,125,144,162,210,209, %U A210717 845,270,32541,346,1885800,443,101215159,565,5025321572 %N A210717 Number of disconnected regular simple graphs on n vertices with girth exactly 7. %H A210717 Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/D_k-reg_girth_eq_g_index">Index of sequences counting disconnected k-regular simple graphs with girth exactly g</a> %F A210717 a(n) = A185217(n) - A185218(n). %K A210717 nonn,more,hard %O A210717 0,22 %A A210717 _Jason Kimberley_, Dec 18 2012