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 A298201 #14 Feb 16 2025 08:33:53
%S A298201 32,114,548,2970,16892,98466,583412,3500970,21232556,129930354,
%T A298201 801132452,4970993658,31006439132,194231313474,1220944803668,
%U A298201 7696445791050,48625129598732,307759067766546,1950657679387652,12377791111168410,78613025212107836,499635602835227874
%N A298201 Number of Eulerian orientations of the torus grid graph C_4 X C_n.
%H A298201 Andrew Howroyd, <a href="/A298201/b298201.txt">Table of n, a(n) for n = 1..200</a>
%H A298201 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TorusGridGraph.html">Torus Grid Graph</a>
%H A298201 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (15,-77,161,-138,40).
%F A298201 a(n) = 15*a(n-1) - 77*a(n-2) + 161*a(n-3) - 138*a(n-4) + 40*a(n-5).
%F A298201 G.f.: 2*x*(16 - 183*x + 651*x^2 - 812*x^3 + 300*x^4)/((1 - x)*(1 - 2*x)*(1 - 5*x)*(1 - 7*x + 4*x^2)).
%t A298201 LinearRecurrence[{15, -77, 161, -138, 40}, {32, 114, 548, 2970, 16892}, 22] (* _Jean-François Alcover_, Sep 21 2019 *)
%o A298201 (PARI) Vec(2*(16 - 183*x + 651*x^2 - 812*x^3 + 300*x^4)/((1 - x)*(1 - 2*x)*(1 - 5*x)*(1 - 7*x + 4*x^2)) + O(x^25))
%Y A298201 Row 4 of A298119.
%Y A298201 Cf. A006240, A298197.
%K A298201 nonn
%O A298201 1,1
%A A298201 _Andrew Howroyd_, Jan 14 2018