A177571 Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, up, up, up

1, 6, 90, 2484, 109339, 7019168, 619051405, 71824824028, 10607707589930, 1943225496142169

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Crossrefs

Sequence in context: A177586 A177579 A177591 * A177590 A177577 A177572

Adjacent sequences: A177568 A177569 A177570 * A177572 A177573 A177574

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved