A190922 Number of permutations of n copies of 1..5 introduced in order 1..5 with no element equal to another within a distance of 3

1, 20, 436, 9993, 238856, 5904049, 149981369, 3897334810, 103211369665, 2777315286064, 75757347740370, 2090701163682622, 58284103429506565, 1639251621061033507, 46464491673819086074, 1326158666350163625126

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n = 1..61

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

Crossrefs

Sequence in context: A130832 A180810 A109116 * A136257 A320765 A099278

Adjacent sequences: A190919 A190920 A190921 * A190923 A190924 A190925

Keyword

nonn

Author

R. H. Hardin May 23 2011

Status

approved