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A177607
Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, down, up.
0
1, 1, 20, 1680, 359582, 156245130, 120386806922, 150097348110878, 283411248751268531
OFFSET
0,3
CROSSREFS
Cf. A014606.
Sequence in context: A266737 A177599 A177600 * A177612 A177618 A177624
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 10 2010
STATUS
approved