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 A210716 #4 Dec 12 2012 11:25:32 %S A210716 0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,2,2,3,3,4,4,6,6,8,9,12,12,17,17, %T A210716 27,24,66,32,472,44,8172,60,191325,80,4856015,107,127937980,143, %U A210716 3482858430,188,98176518479,248 %N A210716 Number of disconnected regular simple graphs on n vertices with girth exactly 6. %H A210716 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 A210716 a(n) = A185216(n) - A185217(n). %K A210716 nonn,more,hard %O A210716 0,19 %A A210716 _Jason Kimberley_, Dec 10 2012