A151588 Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 7 adjacent element pairs in decreasing order.

0, 760, 911520, 222334560, 25996425216, 1996732745784, 117482611237280

Offset

4,2

Links

Table of n, a(n) for n=4..10.

Crossrefs

Sequence in context: A151633 A022051 A107515 * A141144 A139664 A160033

Adjacent sequences: A151585 A151586 A151587 * A151589 A151590 A151591

Keyword

nonn

Author

R. H. Hardin May 21 2009

Status

approved