A177631 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, up, down, down, up, up

1, 20, 1674, 363454, 161958230, 128735444262, 166178950132409, 325628012566801867

Offset

1,2

Links

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

Crossrefs

Sequence in context: A177627 A177620 A177632 * A177292 A266737 A177599

Adjacent sequences: A177628 A177629 A177630 * A177632 A177633 A177634

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved