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 A006927 M3086 #22 Jul 08 2025 16:58:07 %S A006927 0,0,0,0,0,0,0,0,0,0,0,0,1,3,21,545,30368,1782839,95079080,4686063107 %N A006927 Number of connected trivalent graphs with 2n nodes and girth exactly 7. %D A006927 Gordon Royle, personal communication. %D A006927 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006927 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 A006927 a(n) = A014375(n) - A014376(n). %Y A006927 Connected 3-regular simple graphs with girth exactly g: A198303 (triangle); specified g: A006923 (g=3), A006924 (g=4), A006925 (g=5), A006926 (g=6), this sequence (g=7). %Y A006927 Connected 3-regular simple graphs with girth at least g: A002851 (g=3), A014371 (g=4), A014372 (g=5), A014374 (g=6), A014375 (g=7), A014376 (g=8). %K A006927 nonn,hard,more %O A006927 0,14 %A A006927 _N. J. A. Sloane_ %E A006927 Definition amended to include "connected" (no disconnected yet), and "girth at least 7" minus "girth at least 8" formula provided by _Jason Kimberley_, Dec 12 2009