A358648 Number of preference profiles of the stable roommates problem with 2n participants.

1, 1296, 2985984000000, 416336312719673760153600000000, 39594086612242519324387557078266845776303882240000000000, 16363214235219603423192858350259453436046713251360764276842772299776000000000000000000000000

Offset

1,2

Comments

Each participant ranks all participants other than themselves in strict order, giving (2n-1)! orderings for each of 2n participants.

Links

Table of n, a(n) for n=1..6.

Wikipedia, Stable Roommates Problem

Formula

a(n) = (2n-1)!^(2n).

Mathematica

Table[(2n-1)!^(2n), {n, 1, 6}]

Crossrefs

Cf. A356584 (up to isomorphism), A185141 (Stable Marriage profiles), A001147 (possible roommate pairings).

Even bisection of A091868.

Sequence in context: A067492 A222338 A013841 * A256834 A031750 A345956

Adjacent sequences: A358645 A358646 A358647 * A358649 A358650 A358651

Keyword

nonn,easy

Author

Dan Eilers, Nov 24 2022

Status

approved