A177620 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, up, down, down

1, 20, 1668, 359100, 158300844, 124353422844, 158542302936726, 306707541063303576

Offset

1,2

Links

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

Crossrefs

Sequence in context: A177614 A177622 A177627 * A177632 A177631 A177292

Adjacent sequences: A177617 A177618 A177619 * A177621 A177622 A177623

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved