2150688domain: NAppears in sequencesNumber of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 3 local maxima.at n=5A159717Triangle read by rows: T(n,k) is the number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly k local maxima.at n=24A334778