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 A186744 #4 Apr 03 2012 11:56:37 %S A186744 0,0,0,0,1,0,1,0,3,0,8,2,34,31,330,1607,17970,193906,2867269,32674056, %T A186744 1581626328,6705889815 %N A186744 Number of connected regular simple graphs on n vertices with girth exactly 4. %H A186744 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 A186744 a(n) = A186724(n) - A186725(n). %K A186744 nonn,more,hard %O A186744 0,9 %A A186744 _Jason Kimberley_, Apr 03 2012