A177570 - OEIS

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A177570

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

1, 6, 86, 2147, 86337, 5048158, 404763879, 42661639277, 5720539614420, 951006841725136

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

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

CROSSREFS

Sequence in context: A231165 A091881 A004701 * A343636 A369624 A047786

Adjacent sequences: A177567 A177568 A177569 * A177571 A177572 A177573

KEYWORD

nonn

AUTHOR

R. H. Hardin May 10 2010

STATUS

approved