A190926 Number of permutations of n copies of 1..6 introduced in order 1..6 with no element equal to another within a distance of 4

1, 40, 1744, 79944, 3791001, 184877712, 9230302913, 470167308382, 24367956213267, 1282234744431834, 68376498305017644, 3689492332817242036, 201174991614802295504, 11072289690651114833968, 614516844070147078701721

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n = 1..37

Example

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....4....4....4....4....4....4....4....4....4....4....4....4....4....4....4
..5....5....5....5....5....5....5....5....5....5....5....5....5....5....5....5
..6....6....6....1....1....6....6....6....1....6....6....6....6....6....6....6
..2....2....1....6....6....1....1....1....6....1....2....1....2....2....1....2
..1....1....3....3....3....3....2....3....2....3....3....2....3....3....2....3
..4....4....4....2....2....2....3....4....3....2....4....4....1....4....3....4
..5....5....2....4....5....4....5....5....4....5....1....5....4....5....4....5
..3....6....5....5....4....5....4....6....5....6....5....6....5....6....5....1
..6....3....6....6....6....6....6....2....6....4....6....3....6....1....6....6

Crossrefs

Sequence in context: A223609 A145294 A147520 * A143314 A308836 A189503

Adjacent sequences: A190923 A190924 A190925 * A190927 A190928 A190929

Keyword

nonn

Author

R. H. Hardin May 23 2011

Status

approved