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 A005505 M1227 #40 Feb 23 2021 10:06:45 %S A005505 1,2,4,10,29,86,266,844,2742,9032,30202,101988,347914,1195500,4138310, %T A005505 14405848,50428392,177321636,626250990,2219876580,7896651847, %U A005505 28176271634,100830069380,361757157484,1301092926454,4689840961196,16940093338162,61305930699382 %N A005505 Number of unrooted triangulations with reflection symmetry of a quadrilateral with n internal nodes. %C A005505 These are also called [n,1]-triangulations. %D A005505 C. F. Earl and L. J. March, Architectural applications of graph theory, pp. 327-355 of R. J. Wilson and L. W. Beineke, editors, Applications of Graph Theory. Academic Press, NY, 1979. %D A005505 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005505 Andrew Howroyd, <a href="/A005505/b005505.txt">Table of n, a(n) for n = 0..500</a> %H A005505 C. F. Earl and L. J. March, <a href="/A005500/a005500_1.pdf">Architectural applications of graph theory</a>, pp. 327-355 of R. J. Wilson and L. W. Beineke, editors, Applications of Graph Theory. Academic Press, NY, 1979. (Annotated scanned copy) %H A005505 C. F. Earl & N. J. A. Sloane, <a href="/A005500/a005500.pdf">Correspondence, 1980-1981</a> %F A005505 a(n) = 2 * A005500(n) - A002710(n) (based on _Max Alekseyev_'s formula, cf. A005500). %Y A005505 Column k=1 of the array in A169809. %Y A005505 Cf. A002710, A005500. %K A005505 nonn %O A005505 0,2 %A A005505 _N. J. A. Sloane_ %E A005505 a(7)-a(12) from _Altug Alkan_ and _Manfred Scheucher_, Mar 08 2018 %E A005505 Name clarified and terms a(13) and beyond from _Andrew Howroyd_, Feb 21 2021