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 A006143 M1737 #15 Dec 27 2018 07:57:41 %S A006143 0,0,0,1,0,0,2,7,12,14,36,95,226,501,1056,2377,5448 %N A006143 Number of certain self-avoiding walks with n steps on square lattice (see reference for precise definition). %D A006143 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006143 W. A. Beyer and M. B. Wells, <a href="http://dx.doi.org/10.1016/0097-3165(72)90024-6">Lower bound for the connective constant of a self-avoiding walk on a square lattice</a>, J. Combin. Theory, A 13 (1972), 176-182, Table I. %Y A006143 Cf. A002976. %K A006143 nonn,walk,more %O A006143 4,7 %A A006143 _N. J. A. Sloane_