A177623 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, up, up, up

1, 20, 1680, 367262, 165022063, 132375585604, 172527174986381, 341425620652837589

Offset

1,2

Links

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

Crossrefs

Sequence in context: A177624 A177613 A177619 * A177633 A177634 A177293

Adjacent sequences: A177620 A177621 A177622 * A177624 A177625 A177626

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved