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A115509 Number of circular permutations where for every pair of adjacent elements one element in binary notation has ones at the same or adjacent positions to those of the other element. 2
1, 1, 2, 0, 0, 2, 4, 0, 0, 0, 0, 432, 1968, 24960, 161280, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Conjecture: if 2^(k+1)<=n<3*2^k for k>=1, then a(n)=0.

LINKS

Table of n, a(n) for n=1..21.

CROSSREFS

Cf. A115507, A115508.

Sequence in context: A147699 A250023 A151669 * A279360 A134312 A195581

Adjacent sequences:  A115506 A115507 A115508 * A115510 A115511 A115512

KEYWORD

nonn,more

AUTHOR

Max Alekseyev, Jan 31 2006

STATUS

approved

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Last modified October 16 17:36 EDT 2018. Contains 316271 sequences. (Running on oeis4.)