A360517 Number of 2-color vertex orderings of the labeled cycle graph on 2*n vertices.

0, 24, 480, 18816, 1175040, 107796480, 13630955520, 2273062256640, 483283797147648, 127601594573783040, 40960778432654868480, 15710045049427958169600, 7095139411569155034316800, 3726944074638630907382071296, 2252901869996867025766994411520, 1552830650080006456164417892515840

Offset

1,2

Comments

Bouwer and Star give a recurrence.

References

Bouwer, I., and Z. Star. "A question of protocol." The American mathematical monthly 95.2 (1988): 118-121. See C(n).

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

Formula

a(n) = 4*n*(n - 1)*(2*n - 1)*A360514(2*n - 3) for n > 1. - Andrew Howroyd, Feb 27 2023

Prog

(PARI) \\ Needs A360514seq from A360514.
seq(n) = {my(v=A360514seq(2*n-1)); vector(n, n, if(n>1, 4*n*(n-1)*(2*n-1)*v[2*n-3]))} \\ Andrew Howroyd, Feb 27 2023

Crossrefs

Cf. A360514, A360515, A360516.

Sequence in context: A361576 A052715 A052725 * A006548 A159877 A319426

Adjacent sequences: A360514 A360515 A360516 * A360518 A360519 A360520

Keyword

nonn

Author

N. J. A. Sloane, Feb 27 2023.

Extensions

Terms a(6) and beyond from Andrew Howroyd, Feb 27 2023

Status

approved