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 A006660 M0840 #26 Jun 28 2017 15:17:07 %S A006660 1,1,2,3,7,14,36,81,221,538,1530,3926,11510,30694,92114,252939,773259, %T A006660 2172830,6743122,19304190,60658606,176343390,559952824,1649008456, %U A006660 5283239596,15730575554,50789908772,152663683494 %N A006660 Number of meanders in which first bridge is 3. %D A006660 S. K. Lando and A. K. Zvonkin "Plane and projective meanders", Séries Formelles et Combinatoire Algébrique. Laboratoire Bordelais de Recherche Informatique, Université Bordeaux I, 1991, pp. 287-303. %D A006660 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006660 S. K. Lando and A. K. Zvonkin , <a href="/A005316/a005316_1.pdf">Plane and projective meanders</a>, Séries Formelles et Combinatoire Algébrique. Laboratoire Bordelais de Recherche Informatique, Université Bordeaux I, 1991, pp. 287-303. (Annotated scanned copy) %Y A006660 Cf. A259974, A005316. %K A006660 nonn %O A006660 3,3 %A A006660 _Simon Plouffe_ %E A006660 a(19)-a(30) from _Andrew Howroyd_, Dec 15 2015