A177629 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, up, up, up, up.

1, 1, 20, 1680, 369600, 167714730, 136194434423, 179979692293317, 361532596882040400

Offset

0,3

Links

Table of n, a(n) for n=0..8.

Crossrefs

Cf. A014606.

Sequence in context: A177605 A177606 A177617 * A177630 A177294 A177615

Adjacent sequences: A177626 A177627 A177628 * A177630 A177631 A177632

Keyword

nonn

Author

R. H. Hardin, May 10 2010

Status

approved