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 A345246 #9 Jan 15 2023 01:45:13 %S A345246 1,2,6,16,78,415,3374,35860,524386,10193061,263036202,8948113645, %T A345246 400280198048 %N A345246 Number of 2-connected unlabeled simple graphs with no triangles. %e A345246 For n=4 the only example is a 4-cycle. %Y A345246 Cf. A002218 all 2-connected graphs. %Y A345246 Cf. A024607 all connected triangle-free graphs. %K A345246 nonn,hard,more %O A345246 4,2 %A A345246 _Brendan McKay_, Jun 12 2021