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 A066543 #10 Oct 26 2023 08:32:31 %S A066543 782757789696,5976745079881894723584, %T A066543 29514790517935282585600000000000000, %U A066543 95296975201657487970461602120230307486331043840000,202142993853936783750487849288950496428731602354031286611374533246976 %N A066543 Number of spanning trees in the line graph of the product of two cycle graphs, each of order n, L(C_n x C_n). %F A066543 a(n) = 2^(3*n^2-1) * A212800(n). - _Sean A. Irvine_, Oct 25 2023 %e A066543 NumberOfSpanningTrees(L(C_3 x C_3)) = 782757789696 %t A066543 NumberOfSpanningTrees[LineGraph[GraphProduct[Cycle[n], Cycle[n]]]] (* First load package DiscreteMath`Combinatorica` *) %Y A066543 Cf. A212800. %K A066543 nonn %O A066543 3,1 %A A066543 _Roberto E. Martinez II_, Jan 07 2002 %E A066543 Edited by _Dean Hickerson_, Jan 14 2002 %E A066543 a(7) from _Sean A. Irvine_, Oct 25 2023