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

Author

R. H. Hardin, Oct 25 2015

Keywords

• nonn

Comments

Column 2 of A263744

Examples

			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
		

Links

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

Crossrefs

Cf. A263744