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 A103465 #27 Apr 26 2023 07:09:29 %S A103465 1,1,2,7,25,118,551,2812,14445,76092,403976,2167116,11698961,63544050, %T A103465 346821209,1901232614 %N A103465 Number of polyominoes that can be formed from n regular unit pentagons (or polypents of order n). %C A103465 Number of 5-polyominoes with n pentagons. A k-polyomino is a non-overlapping union of n regular unit k-gons. %C A103465 Unlike A051738, these are not anchored polypents but simple polypents. - _George Sicherman_, Mar 06 2006 %C A103465 Polypents (or 5-polyominoes in Koch and Kurz's terminology) can have holes and this enumeration includes polypents with holes. - _George Sicherman_, Dec 06 2007 %H A103465 Erich Friedman, <a href="https://erich-friedman.github.io/mathmagic/">Math Magic</a>, September and November 2004. %H A103465 Matthias Koch and Sascha Kurz, <a href="http://arxiv.org/abs/math/0605144">Enumeration of generalized polyominoes</a> (preprint) arXiv:math.CO/0605144 %H A103465 Sascha Kurz, <a href="http://www.mathe2.uni-bayreuth.de/sascha/oeis/k-polyominoes.html">k-polyominoes</a>. %H A103465 George Sicherman, <a href="https://sicherman.net/polypents/index.html">Catalogue of Polypents</a>, at Polyform Curiosities. %e A103465 a(3)=2 because there are 2 geometrically distinct ways to join 3 regular pentagons edge to edge. %Y A103465 Cf. A103465, A103466, A103467, A103468, A103469, A103470, A103471, A103472, A103473, A120102, A120103, A120104. %Y A103465 Cf. A000105, A000577, A000228. %K A103465 more,nonn %O A103465 1,3 %A A103465 _Sascha Kurz_, Feb 07 2005; definition revised and sequence extended Apr 12 2006 and again Jun 09 2006 %E A103465 Entry revised by _N. J. A. Sloane_, Jun 18 2006