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 A345249 #13 Apr 01 2022 17:28:21 %S A345249 1,2,8,54,548,7984,163440,4599908,174204728,8721120744,568964631296, %T A345249 47787888342520,5112015062311008,689824902243337856, %U A345249 116423739687724785152,24387469030487505651984,6296486009090647137387200,1991072810881504185092485408 %N A345249 Number of labeled simple graphs on n vertices without cycles of length 4. %H A345249 <a href="/index/Sq#square_free">Index entries for sequences of squarefree graphs</a> %Y A345249 EXP transform of A345248. Row sums of A352472. %Y A345249 A006786 counts isomorphism classes. %Y A345249 Cf. A213434, A352258 (loops allowed). %K A345249 nonn,hard %O A345249 1,2 %A A345249 _Brendan McKay_, Jun 12 2021