A263738 Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and equal numbers of elements moved upwards and downwards

1, 2, 4, 10, 19, 43, 90, 202, 434, 971, 2133, 4780, 10634, 23918, 53667, 121159, 273464, 619510, 1404284, 3190779, 7256305, 16529258, 37686110, 86028558, 196547581, 449479587, 1028674074, 2356054490, 5399827384, 12383951473, 28417821421

Offset

1,2

Comments

Column 2 of A263744

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

Some solutions for n=7
..0....2....1....2....1....0....0....1....2....1....0....0....2....2....0....2
..1....0....0....1....0....1....2....3....1....0....1....2....1....1....3....0
..3....3....2....0....3....3....1....0....0....4....2....4....0....0....4....3
..5....1....5....5....2....2....3....5....4....2....3....1....3....5....1....1
..2....4....3....4....4....6....6....2....3....5....5....3....4....3....2....5
..4....5....6....3....5....5....5....4....5....3....4....6....5....6....6....4
..6....6....4....6....6....4....4....6....6....6....6....5....6....4....5....6

Crossrefs

Cf. A263744

Sequence in context: A043330 A295961 A219555 * A011963 A083844 A026554

Adjacent sequences: A263735 A263736 A263737 * A263739 A263740 A263741

Keyword

nonn

Author

R. H. Hardin, Oct 25 2015

Status

approved