A124355 Number of (directed) Hamiltonian cycles on the complete graph K_n.

0, 0, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800, 479001600, 6227020800, 87178291200, 1307674368000, 20922789888000, 355687428096000, 6402373705728000, 121645100408832000, 2432902008176640000

Offset: 1

Author

Eric W. Weisstein, Nov 05 2006

Keywords

• nonn

Comments

a(n) is also the number of (directed) Hamiltonian paths on the complete graph K_{n-1}.

Links

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

Crossrefs

Cf. A000142, A104150.

Formula

a(1) = 0, a(2) = 0, a(n) = (n-1)! = A104150(n) for n > 2. - Georg Fischer, Oct 21 2018