62178928domain: NAppears in sequencesNumber of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 3 local maxima.at n=6A159717Triangle 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=31A334778