A177634 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, up, up, down, down, down

1, 20, 1680, 369240, 167472864, 135960447600, 179637314905576, 360796550854271920

Offset

1,2

Links

Table of n, a(n) for n=1..8.

Crossrefs

Sequence in context: A177619 A177623 A177633 * A177293 A266738 A177605

Adjacent sequences: A177631 A177632 A177633 * A177635 A177636 A177637

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved