172620domain: NAppears in sequencesa(n) = ceiling(A173497(n)/2).at n=40A173508Number of permutations of 1..n with the sequence of sums of 2 adjacent elements having exactly 2 maxima.at n=6A179711Number of permutations of 1..n with the sequence of sums of 2 adjacent elements having exactly 3 maxima.at n=4A179712