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 A006724 M1637 #32 Sep 04 2024 12:02:45 %S A006724 1,2,6,19,63,216,756,2684,9638,34930,127560,468837,1732702,6434322, %T A006724 23993874,89805691,337237337,1270123530,4796310672,18155586993, %U A006724 68874803609,261803388854,996971935098,3802944302442,14528816598358 %N A006724 Number of fixed n-celled self-avoiding polygons on square lattice. %C A006724 Translations, rotations and reflections are not allowed. %D A006724 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006724 I. Jensen, <a href="/A006724/b006724.txt">Table of n, a(n) for n = 1..42</a> (from link below) %H A006724 I. G. Enting and A. J. Guttmann, <a href="http://dx.doi.org/10.1007/BF01112757">On the area of square lattice polygons</a>, J. Statist. Phys., 58 (1990), 475-484. See p. 477. %H A006724 I. Jensen, <a href="https://web.archive.org/web/20160102114247/http://www.ms.unimelb.edu.au/~iwan/polygons/series/square.area.ser">More terms</a> %H A006724 Tomás Oliveira e Silva, <a href="http://sweet.ua.pt/tos/animals.html">Enumeration of polyominoes</a> %H A006724 Hugo Tremblay and Julien Vernay, <a href="https://doi.org/10.1051/ita/2024013">On the generation of discrete figures with connectivity constraints</a>, RAIRO-Theor. Inf. Appl. (2024) Vol. 58, Art. No. 16. See p. 13. %Y A006724 Cf. A002931. %K A006724 nonn,nice %O A006724 1,2 %A A006724 _N. J. A. Sloane_, _Simon Plouffe_