A307924 Number of (undirected) Hamiltonian cycles in the complete tripartite graph K_{n,n,n}.

1, 16, 1584, 463104, 299289600, 361552896000, 732443959296000, 2305449150971904000, 10654390419268829184000, 69202145783548005580800000, 610152377325314475294720000000, 7098963015274747190071787520000000, 106459726394067298796772293345280000000, 2017443502989317777418537171765166080000000

Offset: 1

Author

Eric W. Weisstein, May 06 2019

Keywords

• nonn

Links

• Eric Weisstein's World of Mathematics, Complete Tripartite Graph
• Eric Weisstein's World of Mathematics, Hamiltonian Cycle

Crossrefs

Cf. A234365.

Programs

Mathematica

Table[2^(n - 1) (n - 1)! (n!)^2 HypergeometricPFQ[{1/2 - n/2, -n/2, n}, {1, 1}, 1], {n, 20}] (* Eric W. Weisstein, Feb 19 2025 *)

Formula

a(n) = A234365(n)/2.