

A242524


Number of cyclic arrangements of S={1,2,...,n} such that the difference between any two neighbors is at least 4.


16



0, 0, 0, 0, 0, 0, 0, 0, 1, 24, 504, 8320, 131384, 2070087, 33465414, 561681192, 9842378284, 180447203232, 3462736479324, 69517900171056, 1458720714556848, 31955023452174314, 729874911380470641, 17359562438053760533, 429391730229931885360
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OFFSET

1,10


COMMENTS

a(n)=NPC(n;S;P) is the count of all neighborproperty cycles for a specific set S of n elements and a specific pairproperty P. For more details, see the link and A242519.


LINKS

Hiroaki Yamanouchi, Table of n, a(n) for n = 1..27 (terms a(1)a(16) from Stanislav Sykora)
S. Sykora, On NeighborProperty Cycles, Stan's Library, Volume V, 2014.


EXAMPLE

The shortest such cycle has length n=9: {1,5,9,4,8,3,7,2,6}.


PROG

(C++) See the link.


CROSSREFS

Cf. A242519, A242520, A242521, A242522, A242523, A242525, A242526, A242527, A242528, A242529, A242530, A242531, A242532, A242533, A242534.
Sequence in context: A112390 A166757 A289833 * A264956 A055007 A014907
Adjacent sequences: A242521 A242522 A242523 * A242525 A242526 A242527


KEYWORD

nonn,hard


AUTHOR

Stanislav Sykora, May 27 2014


EXTENSIONS

a(17)a(25) from Hiroaki Yamanouchi, Aug 29 2014


STATUS

approved



