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 A307387 #74 Apr 22 2019 11:46:29 %S A307387 1,9,191,8049,418184,24283599 %N A307387 a(n) is the number of canonical polygons with 4n alternating straight and diagonal edges. %H A307387 Lars Blomberg, <a href="/A307387/a307387.pdf">Examples of canonical polygons with alternating straight and diagonal edges</a> %Y A307387 Cf. A052436, A307387, A307391, A307426, A307454, A307455, A307456, A307519. %K A307387 nonn,more %O A307387 1,2 %A A307387 _Lars Blomberg_, Apr 18 2019