A177625 Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, up, down, up, down.

1, 20, 1572, 320232, 132684888, 97774021472, 116814354490224, 211630469311857952

Offset

1,2

Links

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

Crossrefs

Sequence in context: A200900 A177603 A160308 * A203481 A177608 A177610

Adjacent sequences: A177622 A177623 A177624 * A177626 A177627 A177628

Keyword

nonn

Author

R. H. Hardin, May 10 2010

Status

approved