A066545 Number of spanning trees in the line graph of the product of two complete graph, each of order n, L(K_n x K_n).

4, 782757789696, 391497025772177207236260602767731880976449536, 79571717825565862744861159703491334416072984127575634790474236302905519522005340085288960000000000000000000000

Offset: 2

Author

Roberto E. Martinez II, Jan 07 2002

Keywords

• hard
• nonn

Comments

a(2) = 2^2, a(3) = 2^30 * 3^6, a(4) = 2^99 * 3^31, a(5) = 2^314 * 5^22. - Gerald McGarvey, Oct 20 2007

Examples

			NumberOfSpanningTrees(L(K_2 x K_2)) = 4.
		

Programs

Mathematica

NumberOfSpanningTrees[LineGraph[GraphProduct[CompleteGraph[n], CompleteGraph[n]]]] (* First load package DiscreteMath`Combinatorica` *)

Extensions

Edited by Dean Hickerson, Jan 14 2002