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A177608
Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, down, down, up, down
0
1, 20, 1586, 315125, 126303569, 89413719314, 102170147565708, 176499204309919562
OFFSET
1,2
CROSSREFS
Sequence in context: A160308 A177625 A203481 * A177610 A130040 A331563
KEYWORD
nonn
AUTHOR
R. H. Hardin May 10 2010
STATUS
approved