A177660 Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, down, up, up.

1, 70, 34650, 62484750, 297230343314, 3080473154954302, 61234390521656478875

Offset

1,2

Links

Table of n, a(n) for n=1..7.

Crossrefs

Sequence in context: A177659 A177665 A177654 * A177664 A177674 A177675

Adjacent sequences: A177657 A177658 A177659 * A177661 A177662 A177663

Keyword

nonn

Author

R. H. Hardin, May 10 2010

Status

approved