A151599 Number of permutations of 4 indistinguishable copies of 1..n arranged in a circle with exactly 4 adjacent element pairs in decreasing order.

0, 2, 13485, 2273540, 167274075, 8894295174, 406137173897

Offset

1,2

Links

Table of n, a(n) for n=1..7.

Crossrefs

Sequence in context: A094212 A070832 A170994 * A297573 A346566 A159730

Adjacent sequences: A151596 A151597 A151598 * A151600 A151601 A151602

Keyword

nonn

Author

R. H. Hardin May 21 2009

Status

approved