A190923 Number of permutations of n copies of 1..6 introduced in order 1..6 with no element equal to another within a distance of 1.

1, 3655, 22831355, 182502973885, 1681287695542855, 16985819072511102549, 183095824753841610373405, 2070756746775910218326948065, 24302858067615766089801166488125, 293736218147318801678882792470437721

Offset: 1

Author

R. H. Hardin, May 23 2011

Keywords

• nonn

Examples

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

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..240 (terms 1..35 from R. H. Hardin)

Crossrefs

Column k=6 of A322013.

Cf. A000012 (b=2), A190917 (b=3), A190918 (b=4), A190920 (b=5), A190927 (b=7), A190932 (b=8), A321987 (b=9).

Formula

a(n) ~ 9 * 5^(6*n-2) / (128 * sqrt(2) * Pi^(5/2) * n^(5/2)). - Vaclav Kotesovec, Nov 24 2018