260800domain: NAppears in sequencesa(n) = [x^n] ( E(x)/E(-x) )^n where E(x)= exp( Sum_{k >= 1} A005259(k)*x^k/k ).at n=4A362723Variation of triangle of Entringer numbers (A008281) read by rows: T(n, k) = T(n, k-1) + (n-2)*T(n-1, n-k) for 1 < k <= n, T(n, 1) = T(n-1, n-1) for n > 0, T(n, 0) = 0^n.at n=42A386363