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 A006926 M3969 #26 Jul 08 2025 16:58:01 %S A006926 0,0,0,0,0,0,0,1,1,5,32,385,7573,181224,4624480,122089998,3328899586, %T A006926 93988909755 %N A006926 Number of connected trivalent graphs with 2n nodes and girth exactly 6. %D A006926 CRC Handbook of Combinatorial Designs, 1996, p. 647. %D A006926 Gordon Royle, personal communication. %D A006926 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006926 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 A006926 a(n) = A014374(n) - A014375(n). %Y A006926 Connected 3-regular simple graphs with girth exactly g: A198303 (triangle); specified g: A006923 (g=3), A006924 (g=4), A006925 (g=5), this sequence (g=6), A006927 (g=7). %Y A006926 Connected 3-regular simple graphs with girth at least g: A185131 (triangle); A002851 (g=3), A014371 (g=4), A014372 (g=5), A014374 (g=6), A014375 (g=7), A014376 (g=8). %K A006926 nonn,hard,more %O A006926 0,10 %A A006926 _N. J. A. Sloane_ %E A006926 Definition corrected to include "connected", and "girth at least 6" minus "girth at least 7" formula provided by _Jason Kimberley_, Dec 12 2009