A177645 Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, up, down, down

1, 70, 32988, 53577384, 223138602958, 1992266686369568, 33770993367805159464

Offset

1,2

Links

Table of n, a(n) for n=1..7.

Crossrefs

Sequence in context: A146499 A177649 A177651 * A177662 A177669 A177667

Adjacent sequences: A177642 A177643 A177644 * A177646 A177647 A177648

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved