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 A252863 #16 Dec 28 2014 23:54:16 %S A252863 1,16,304,5824,111616,2139136,40996864,785711104,15058272256, %T A252863 288594067456,5530948993024,106001474781184,2031534311735296, %U A252863 38934662638206976,746188703776374784,14300819473316184064,274077370205901684736,5252734292544974749696 %N A252863 Number of Eulerian paths in a lattice graph bounded by the four equations x+y=1, x+y=2n, x-y=2, and x-y=-2. %H A252863 Muhammad Kholilurrohman, <a href="/A252863/b252863.txt">Table of n, a(n) for n = 1..300</a> %H A252863 P. Audibert, <a href="http://as.wiley.com/WileyCDA/WileyTitle/productCd-1848211961.html">Mathematics for Informatics and Computer Science</a>, Wiley, 2010, p. 824. %H A252863 Muhammad Kholilurrohman and Shin-ichi Minato, <a href="http://www-alg.ist.hokudai.ac.jp/~thomas/TCSTR/tcstr_14_77/tcstr_14_77.pdf">An Efficient Algorithm for Enumerating Eulerian Paths</a>, Hokkaido University, Division of Computer Science, TCS Technical Reports, TCS-TR-A-14-77, Oct. 2014. %F A252863 Empirical g.f.: (x - 4*x^2)/(1 - 20*x + 16*x^2) and recurrence a(n) = 20*a(n-1) - 16*a(n-2). - _Robert Israel_, Dec 26 2014 %K A252863 nonn %O A252863 1,2 %A A252863 _Muhammad Kholilurrohman_, Dec 23 2014