login
A177588
Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, up, up, up, up
0
1, 6, 90, 2520, 113160, 7441949, 674077493, 80453033424, 12236281595093, 2310183602289482
OFFSET
1,2
CROSSREFS
Sequence in context: A177564 A177565 A177576 * A177589 A177285 A177574
KEYWORD
nonn
AUTHOR
R. H. Hardin May 10 2010
STATUS
approved