A177573 Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, up, down, up, up

1, 6, 89, 2436, 106394, 6773372, 592215536, 68125576354, 9976045410328, 1812109480941532

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Crossrefs

Sequence in context: A355187 A100297 A177568 * A166782 A121249 A113404

Adjacent sequences: A177570 A177571 A177572 * A177574 A177575 A177576

Keyword

nonn

Author

R. H. Hardin May 10 2010

Status

approved