A151581 Number of permutations of 1..n arranged in a circle with exactly 8 adjacent element pairs in decreasing order.

0, 9, 5020, 526240, 26441856, 862140162, 21078701112, 419567641380, 7160621079552, 108507581733075, 1496470017336660, 19127489390389332, 229712892700188480, 2619711824193741060, 28608047711740408560, 301155410573256748920, 3072652643940279427584

Offset

8,2

Links

Andrew Howroyd, Table of n, a(n) for n = 8..500

Formula

a(n) = n*A001244(n-1). - Andrew Howroyd, May 05 2020

Crossrefs

Column k=8 of A334218.

Cf. A001244.

Sequence in context: A323337 A167064 A125541 * A145263 A185821 A133248

Adjacent sequences: A151578 A151579 A151580 * A151582 A151583 A151584

Keyword

nonn

Author

R. H. Hardin, May 21 2009

Extensions

Terms a(17) and beyond from Andrew Howroyd, May 05 2020

Status

approved