A190946 Number of permutations of the n*(n+1)/2 numbers (i copies of i | i=1..n), with no element equal to another within a distance of 2

1, 0, 0, 10, 13002, 235766334, 82210519761384, 695361269455212253944, 168167463535759034846785492680, 1325777080702697500591757770103358112608, 381104792645297511721802786471971556694067218792480

Offset

1,4

Links

Table of n, a(n) for n=1..11.

Example

All solutions for n=4
..4....4....4....4....4....4....4....4....4....4
..3....3....3....3....1....2....3....3....3....2
..2....1....1....2....3....3....2....2....2....3
..4....4....4....4....4....4....4....4....4....4
..3....2....3....3....2....2....1....3....3....1
..2....3....2....1....3....3....3....2....1....3
..4....4....4....4....4....4....4....4....4....4
..3....2....3....3....2....1....2....1....2....2
..1....3....2....2....3....3....3....3....3....3
..4....4....4....4....4....4....4....4....4....4

Crossrefs

Sequence in context: A151582 A318794 A229229 * A052498 A179425 A203466

Adjacent sequences: A190943 A190944 A190945 * A190947 A190948 A190949

Keyword

nonn

Author

R. H. Hardin May 24 2011

Status

approved