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 A174001 #12 Feb 16 2025 08:33:12 %S A174001 9,632025,23057815104,763341471963225,24743382596536452489, %T A174001 797880028172050676793600,25694231385152383926116001849, %U A174001 827147402338052897443922764419225,26625078176206788678765153788526329856 %N A174001 Number of spanning trees in C_9 X P_n. %H A174001 Alois P. Heinz, <a href="/A174001/b174001.txt">Table of n, a(n) for n = 1..70</a> %H A174001 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CycleGraph.html">Cycle Graph</a> %H A174001 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PathGraph.html">Path Graph</a> %H A174001 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SpanningTree.html">Spanning Tree</a> %F A174001 See program. %p A174001 a:= n-> 9* (Matrix([[0, 1, 265, 50616, 9209545, 1658090689, 297747101520, 53431400864569, 9586723471888105][1+abs(i)]$i=-7..8]). Matrix(16, (i, j)-> if i=j-1 then 1 elif j=1 then [[-427427424, 327381265, -146975161, 38357160, -5699687, 457655, -17736, 265, -1][1+abs(k)]$k=-7..8][i] else 0 fi)^n)[1, 8]^2: seq(a(n), n=1..20); %Y A174001 9th column of A173958. %Y A174001 Cf. A000012, A001542, A003690, A003753, A003733, A158880, A158898. %K A174001 nonn,easy %O A174001 1,1 %A A174001 _Alois P. Heinz_, Nov 26 2010