A177636 Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down.

1, 26, 2506, 624446, 322530466, 301458657626, 465560613932206, 1112284734271280846

Offset

1,2

Links

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

Crossrefs

Sequence in context: A363990 A201623 A087616 * A232159 A263946 A358164

Adjacent sequences: A177633 A177634 A177635 * A177637 A177638 A177639

Keyword

nonn

Author

R. H. Hardin, May 10 2010

Extensions

a(8) from Alois P. Heinz, Oct 22 2013

Status

approved