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 A226917 #20 May 15 2020 04:40:24
%S A226917 1,4,9,25,58,142,324,748,1672,3736,8208,17968,38944,84064,180288,
%T A226917 385216,819328
%N A226917 Number of non-sphere-homeomorphic crossing optimal 2-page book drawings of complete graph K_{2n+1}.
%H A226917 Bernardo M. Ábrego, Oswin Aichholzer, Silvia Fernández-Merchant, Pedro Ramos, Gelasio Salazar, <a href="http://arxiv.org/abs/1206.5669">The 2-Page Crossing Number of K_n</a>, arXiv:1206.5669 [math.CO], 2012.
%H A226917 Bernardo M. Ábrego, Oswin Aichholzer, Silvia Fernández-Merchant, Pedro Ramos, Gelasio Salazar, <a href="http://dx.doi.org/10.1007/s00454-013-9514-0">The 2-Page Crossing Number of K_n</a>, Discrete Comput. Geom. 49 (2013), no. 4, 747--777. MR3068573
%F A226917 Conjecture: a(n) = 4*a(n-1) - 2*a(n-2) - 8*a(n-3) + 8*a(n-4); g.f.: -x^2*(5*x^3-5*x^2+1) / ((2*x-1)^2*(2*x^2-1)). - _Colin Barker_, May 08 2014
%Y A226917 Cf. A000241.
%K A226917 nonn,more
%O A226917 2,2
%A A226917 _N. J. A. Sloane_, Jul 01 2013