A177607 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, down, up.

1, 1, 20, 1680, 359582, 156245130, 120386806922, 150097348110878, 283411248751268531

Offset

0,3

Links

Table of n, a(n) for n=0..8.

Crossrefs

Cf. A014606.

Sequence in context: A266737 A177599 A177600 * A177612 A177618 A177624

Adjacent sequences: A177604 A177605 A177606 * A177608 A177609 A177610

Keyword

nonn

Author

R. H. Hardin, May 10 2010

Status

approved