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 A360608 #11 Feb 14 2023 16:32:25 %S A360608 1,0,2,1,8,12,45,98,292,725,2004,5210,14051,37126,99336,263991,704622, %T A360608 1876566,5005327,13341292,35579622,94866875,252998042,674677856, %U A360608 1799331865,4798687520,12798199466,34133165825,91035612400,242799614636,647572193925,1727149489058 %N A360608 Number of solutions to a 4 X n Ring-Ring puzzle on an empty grid. %H A360608 George Spahn, <a href="https://arxiv.org/abs/2202.06234">Enumerating solutions to grid based puzzles with a fixed number of rows</a>, arXiv:2202.06234 [math.CO], Feb 2022. %H A360608 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (3,3,-10,-3,5,1). %F A360608 G.f.: -(2*x^2 + x - 1)*(x^2 + 2*x - 1)/(x^6 + 5*x^5 - 3*x^4 - 10*x^3 + 3*x^2 + 3*x - 1). %K A360608 nonn,easy %O A360608 0,3 %A A360608 _George Spahn_, Feb 13 2023