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 A359987 #16 Nov 03 2024 12:24:34
%S A359987 1,11,105,919,7713,63351,514321,4148839,33347041,267489431,2143168305,
%T A359987 17160184519,137349160833,1099102033911,8794224638161,70360221445159,
%U A359987 562911076526881,4503422288363351,36027988077717105,288226686123491719,2305826176955087553,18446667292472959671
%N A359987 Number of edge cuts in the n-ladder graph P_2 X P_n.
%H A359987 Andrew Howroyd, <a href="/A359987/b359987.txt">Table of n, a(n) for n = 1..500</a>
%H A359987 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/EdgeCut.html">Edge Cut</a>.
%H A359987 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LadderGraph.html">Ladder Graph</a>.
%H A359987 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (13,-42,16).
%F A359987 a(n) = 13*a(n-1) - 42*a(n-2) + 16*a(n-3) for n > 3.
%F A359987 a(n) = A013730(n-1) - A107839(n-1).
%F A359987 G.f.: x*(1 - 2*x + 4*x^2)/((1 - 8*x)*(1 - 5*x + 2*x^2)).
%t A359987 LinearRecurrence[{13, -42, 16}, {1, 11, 105}, 25] (* _Paolo Xausa_, Jun 24 2024 *)
%t A359987 Table[2^(3 n - 2) + (((5 - Sqrt[17])/2)^n - ((5 + Sqrt[17])/2)^n)/Sqrt[17], {n, 20}] // Expand (* _Eric W. Weisstein_, Nov 03 2024 *)
%t A359987 CoefficientList[Series[-(1 - 2 x + 4 x^2)/((-1 + 8 x) (1 - 5 x + 2 x^2)), {x, 0, 20}], x] (* _Eric W. Weisstein_, Nov 03 2024 *)
%o A359987 (PARI) Vec((1 - 2*x + 4*x^2)/((1 - 8*x)*(1 - 5*x + 2*x^2)) + O(x^25))
%Y A359987 Row 2 of A359990.
%Y A359987 Cf. A013730, A107839, A356828 (vertex cuts), A359989.
%Y A359987 Cf. A359621, A359622.
%K A359987 nonn,easy
%O A359987 1,2
%A A359987 _Andrew Howroyd_, Jan 28 2023