A334780 Total number of local maxima in all permutations of 2 indistinguishable copies of 1..n arranged in a circle.

1, 8, 168, 6336, 360000, 28728000, 3067243200, 422479411200, 72968229734400, 15446903472000000, 3933958530902400000, 1186723982675911680000, 418497083472072084480000, 170595438771094235458560000, 79604772050991371184000000000, 42160341403338557272473600000000

Offset: 1

Author

Andrew Howroyd, May 13 2020

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A334778.

Programs

PARI

\\ CircPeaksBySig defined in A334778.
a(n)={my(u=CircPeaksBySig(vector(n, i, 2), [1..n])); sum(k=1, #u, k*u[k])}

Formula

a(n) = Sum_{k=1..n} k*A334778(n,k).