A159720 Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 6 local maxima.

0, 0, 0, 0, 0, 40272, 62954948, 24342647424, 5320007368884, 848044852469680, 111078667024032048, 12769013592631944576, 1340902091662029846456, 132008300342568131914656, 12398363733385845967412220, 1124539850663707285433353472, 99357839137277548804214431980

Offset: 1

Author

R. H. Hardin, Apr 20 2009

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..200

Crossrefs

Column 6 of A334778.

Cf. A159716.

Programs

PARI

\\ CircPeaksBySig defined in A334778.
a(n) = {CircPeaksBySig(vector(n, i, 2), [6])[1]} \\ Andrew Howroyd, May 13 2020

Extensions

Terms a(10) and beyond from Andrew Howroyd, May 13 2020