A358814 Number of spanning trees in C_9 X C_n.

9, 34928082, 5312031978672, 344499209234302500, 16463182598208445194045, 687776414074843514847584256, 26818349084747196820449212376063, 1005049441217682470864686231147005000, 36735015407753190053984060991247792275456

Offset

1,1

Links

Table of n, a(n) for n=1..9.

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(9, n);

Crossrefs

Row 9 of A212796.

Sequence in context: A131678 A229687 A029983 * A225775 A154110 A235400

Adjacent sequences: A358811 A358812 A358813 * A358815 A358816 A358817

Keyword

nonn

Author

Seiichi Manyama, Dec 02 2022

Status

approved