A177619 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, down, up, up

1, 20, 1680, 367082, 164721913, 131886772257, 171507866127356, 338575969590494675

Offset

1,2

Links

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

Crossrefs

Sequence in context: A177618 A177624 A177613 * A177623 A177633 A177634

Adjacent sequences: A177616 A177617 A177618 * A177620 A177621 A177622

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved