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A217887 Number of n element 1..n arrays with each element the minimum of 4 adjacent elements of a permutation of 1..n+3 of n+3 elements 0
1, 3, 11, 45, 196, 898, 4272, 21002, 106564, 558780, 3037926, 17203726, 101981944, 635338608 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A217891

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

Some solutions for n=4

..1....4....1....2....2....1....1....1....3....4....3....1....4....1....1....1

..3....1....4....2....2....2....2....1....3....3....2....1....2....1....3....3

..2....1....2....1....3....4....2....3....1....1....2....2....1....1....3....4

..2....1....2....1....1....3....2....3....1....1....1....4....1....3....2....2

CROSSREFS

Sequence in context: A049172 A049155 A063024 * A151129 A151130 A216949

Adjacent sequences:  A217884 A217885 A217886 * A217888 A217889 A217890

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 14 2012

STATUS

approved

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Last modified January 15 18:47 EST 2019. Contains 319170 sequences. (Running on oeis4.)