A177642 Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, down, up.

1, 70, 28854, 39663852, 137560321238, 1013521185982046, 14098691799360001768, 339727163188995946031850

Offset

1,2

Links

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

Crossrefs

Sequence in context: A274646 A005983 A200313 * A177644 A146499 A177649

Adjacent sequences: A177639 A177640 A177641 * A177643 A177644 A177645

Keyword

nonn

Author

R. H. Hardin, May 10 2010

Extensions

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

Status

approved