login
A177286
Number of permutations of 2 copies of 1..n with all adjacent differences <= 5 in absolute value.
0
1, 6, 90, 2520, 113400, 7484400, 349272000, 12629539440, 394462558980, 11673071453460, 348672825749478
OFFSET
1,2
COMMENTS
a(n)=(2n)!/2^n for n<=6
CROSSREFS
Sequence in context: A177285 A177574 A177575 * A177594 A177287 A177288
KEYWORD
nonn
AUTHOR
R. H. Hardin May 06 2010
STATUS
approved