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%I #5 Jun 24 2014 01:08:19
%S 4,5976745079881894723584,
%T 22561207271999971793667241231967232556265564782280146786713600000000
%N Number of spanning trees in the line graph of the product of two (2 x n) grid graphs.
%t NumberOfSpanningTrees[LineGraph[GraphProduct[GridGraph[2, n], GridGraph[2, n]]]] (* First load package DiscreteMath`Combinatorica` *)
%K nonn,bref
%O 1,1
%A _Roberto E. Martinez II_, Jan 07 2002
%E Edited by _Dean Hickerson_, Jan 14, 2002