681984domain: NAppears in sequencesNumber of singly defective permutations of 1..n+4 with exactly 3 maxima.at n=3A183266T(n,k) is the number of singly defective permutations of 1..n+2*k-2 with exactly k maxima.at n=18A183270G.f. A(x) satisfies: Sum_{n>=1} (-1)^n * (A(x) - (-1)^n*A(-x))^n = 0.at n=9A317999