A177624 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, up, down, down, down

1, 20, 1680, 365640, 163278207, 130045765680, 168183116878961, 330118679949056240

Offset

1,2

Links

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

Crossrefs

Sequence in context: A177607 A177612 A177618 * A177613 A177619 A177623

Adjacent sequences: A177621 A177622 A177623 * A177625 A177626 A177627

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved