A177308 Number of permutations of 7 copies of 1..n with all adjacent differences <= 2 in absolute value.

1, 1, 3432, 399072960, 5188083048720, 39956935830445136, 452976400962846092338

Offset

0,3

Comments

a(n) = (7n)!/5040^n for n<=3.

Links

Table of n, a(n) for n=0..6.

Crossrefs

Cf. A172603.

Sequence in context: A140911 A351486 A362172 * A177309 A172603 A172559

Adjacent sequences: A177305 A177306 A177307 * A177309 A177310 A177311

Keyword

nonn

Author

R. H. Hardin, May 06 2010

Status

approved