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 A289471 #13 May 04 2021 15:24:54 %S A289471 1,0,1,1,2,3,7,15,39,106,316,1030,3553,13006,49780,197281,804649, %T A289471 3358885,14289507,61769577 %N A289471 Number of planar strictly 2-connected graphs on n edges. %F A289471 a(n) = A343869(n) - A002840(n). - _Andrew Howroyd_, May 04 2021 %Y A289471 Cf. A002218, A002840, A289470, A343869. %K A289471 nonn,more %O A289471 1,5 %A A289471 _Ed Pegg Jr_, Jul 06 2017 %E A289471 a(12)-a(13) corrected and a(14)-a(20) from _Andrew Howroyd_, May 04 2021