A177628 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, up, up, down, up

1, 20, 1635, 342601, 146163330, 110811673197, 136132704627644, 253516051052571276

Offset

1,2

Links

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

Crossrefs

Sequence in context: A250018 A177604 A177621 * A177626 A177609 A094035

Adjacent sequences: A177625 A177626 A177627 * A177629 A177630 A177631

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved