

A174074


Number of circular permutations of length n without consecutive triples i,i+2,i+4.


4



22, 109, 657, 4625, 37186, 336336, 3379058, 37328103, 449669577, 5866178493, 82387080624
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OFFSET

5,1


COMMENTS

Circular permutations are permutations whose indices are from the ring of integers modulo n.


LINKS

Table of n, a(n) for n=5..15.


EXAMPLE

Since a(5)=22, there are (51)!22=2 circular permutations with consecutive triples i,i+2,i+4 in all circular permutations of length 5. They are exactly (0,2,4,1,3) and (0,2,4,3,1).


CROSSREFS

Cf. A165961, A174072, A174073, A174075.
Sequence in context: A124950 A126409 A233299 * A261534 A041938 A084013
Adjacent sequences: A174071 A174072 A174073 * A174075 A174076 A174077


KEYWORD

nonn


AUTHOR

Isaac Lambert, Mar 06 2010


EXTENSIONS

a(10)a(15) from Donovan Johnson, Sep 24 2010


STATUS

approved



