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 A006661 M2286 #28 Jun 28 2017 15:17:12 %S A006661 3,3,7,11,28,57,155,353,1003,2458,7214,18575,55880,149183,457639, %T A006661 1255933,3914103,10978240,34663182,98953078,315884786,915008430, %U A006661 2948378068,8645874055,28084475514,83222134020 %N A006661 Number of meanders in which first bridge is 5. %D A006661 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 A006661 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006661 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 A006661 Cf. A259974, A005316. %K A006661 nonn %O A006661 5,1 %A A006661 _Simon Plouffe_ %E A006661 Offset corrected terms a(19)-a(30) added, _Andrew Howroyd_, Dec 15 2015