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A177576
Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, down, down, down, up
0
1, 6, 90, 2520, 113088, 7424684, 670975605, 79869925320, 12112341959240, 2279762517045300
OFFSET
1,2
CROSSREFS
Sequence in context: A266735 A177564 A177565 * A177588 A177589 A177285
KEYWORD
nonn
AUTHOR
R. H. Hardin May 10 2010
STATUS
approved