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 A184961 #7 May 01 2014 02:36:24 %S A184961 1,1,4,21,266,7849,1,367860,0,21609300,1,1470293675,1,113314233808,9, %T A184961 9799685588936,6 %N A184961 Irregular triangle C(n,g) read by rows, counting the connected 6-regular simple graphs on n vertices with girth at least g. %C A184961 The first column is for girth at least 3. The row length sequence starts: 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3. The row length is incremented to g-2 when n reaches A054760(6,g). %H A184961 Andries E. Brouwer, <a href="http://www.win.tue.nl/~aeb/graphs/cages/cages.html">Cages</a> %H A184961 Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/C_k-reg_girth_ge_g_index">Index of sequences counting connected k-regular simple graphs with girth at least g</a> %e A184961 Triangle begins: %e A184961 1; %e A184961 1; %e A184961 4; %e A184961 21; %e A184961 266; %e A184961 7849, 1; %e A184961 367860, 0; %e A184961 21609300, 1; %e A184961 1470293675, 1; %e A184961 113314233808, 9; %e A184961 9799685588936, 6; %Y A184961 Connected 6-regular simple graphs with girth at least g: this sequence (triangle); chosen g: A006822 (g=3), A058276 (g=4). %Y A184961 Connected 6-regular simple graphs with girth exactly g: A184960 (triangle); chosen g: A184963 (g=3), A184964 (g=4). %Y A184961 Triangular arrays C(n,g) counting connected simple k-regular graphs on n vertices with girth at least g: A185131 (k=3), A184941 (k=4), A184951 (k=5), this sequence (k=6), A184971 (k=7), A184981 (k=8). %K A184961 nonn,hard,more,tabf %O A184961 7,3 %A A184961 _Jason Kimberley_, Jan 10 2012