A177638 Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down.

1, 70, 25446, 29416791, 83400344760, 492319974701196, 5405431813676888595, 101632942861784833336188

Offset

1,2

Links

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

Crossrefs

Sequence in context: A002829 A177637 A145410 * A274646 A005983 A200313

Adjacent sequences: A177635 A177636 A177637 * A177639 A177640 A177641

Keyword

nonn

Author

R. H. Hardin, May 10 2010

Extensions

a(8) from Alois P. Heinz, Nov 02 2013

Status

approved