A177569 Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, up, down, down

1, 6, 88, 2328, 96960, 5846821, 481944258, 52084697975, 7147002322581, 1214148768638010

Offset

1,2

Links

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

Crossrefs

Sequence in context: A218260 A177567 A177563 * A327645 A309165 A127183

Adjacent sequences: A177566 A177567 A177568 * A177570 A177571 A177572

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved