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 A103464 #17 Dec 10 2023 14:46:01 %S A103464 1,1,2,7,25,118,558,2876,14982,80075,431889,2354991,12930257,71459124, %T A103464 396978189,2215609864 %N A103464 Number of polyominoes consisting of n regular unit heptagons. %H A103464 Matthias Koch and Sascha Kurz, <a href="https://arxiv.org/abs/math/0605144">Enumeration of generalized polyominoes</a>, arXiv:math/0605144 [math.CO], 2006. %Y A103464 Cf. A000577, A000104, A000228, A103466, A103467, A103468, A103469, A103470, A103471, A103472, A103473, A120102, A120103, A120104. %K A103464 nonn,more %O A103464 3,3 %A A103464 _Sascha Kurz_, Jun 09 2006