A358810 Number of spanning trees in C_5 X C_n.

5, 16810, 10609215, 4381392020, 1562500000000, 522217835532030, 168437773747672835, 53095647535975155240, 16463182598208445194045, 5040439500800000000000000, 1527650417538030913166754055, 459160235715332056282793308860

Offset

1,1

Links

Table of n, a(n) for n=1..12.

Eric Weisstein's World of Mathematics, Spanning Tree

Eric Weisstein's World of Mathematics, Torus Grid Graph

Prog

(PARI) default(realprecision, 120);
T(n, k) = round(n*k*prod(a=1, n-1, prod(b=1, k-1, 4*sin(a*Pi/n)^2+4*sin(b*Pi/k)^2)));
a(n) = T(5, n);

Crossrefs

Row 5 of A212796.

Sequence in context: A083976 A013834 A263684 * A191940 A055380 A201002

Adjacent sequences: A358807 A358808 A358809 * A358811 A358812 A358813

Keyword

nonn

Author

Seiichi Manyama, Dec 02 2022

Status

approved