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

1, 3, 11, 45, 196, 898, 4272, 21002, 106564, 558780, 3037926, 17203726, 101981944, 635338608

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