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A277265
Multi-table menage seating arrangements: T(n,k) for n,k >= 1 equals the number of ways to seat n*k married couples at n unlabeled round tables with 2*k unlabeled seats each, such that (i) the gender of persons alternates around each table; and (ii) spouses do not sit next to each other.
2
0, 1, 0, 2, 12, 2, 9, 1200, 3280, 12, 44, 498960, 97193600, 5972400, 312, 265, 415981440, 14591060915200, 73866846715200, 31918489344, 9600, 1854, 615853022400, 7390721380256614400, 9022243072072662432000, 287350869074488547328, 393956489203200, 416880, 14833, 1477095102362880
OFFSET
1,4
COMMENTS
For labeled version, see A277257.
FORMULA
T(n,k) = A277256(n,k) * (n*k)! / n! / k^n.
EXAMPLE
Table T(n,k):
n=1: 0, 0, 2, 12, 312, 9600, ...
n=2: 1, 12, 3280, 5972400, ...
n=3: 2, 1200, 97193600, ...
n=4: 9, 498960, 14591060915200, ...
...
CROSSREFS
Cf. A094047 (row n=1), A000166 (column k=1), A277256, A277257.
Sequence in context: A227830 A299521 A167164 * A263631 A010239 A320975
KEYWORD
nonn,tabl
AUTHOR
Max Alekseyev, Oct 07 2016
STATUS
approved