143586domain: NAppears in sequencesTriangle read by rows: T(n,k) is the number of permutations of{1,2,...,n} avoiding [x,x+1] having genus k (see first comment for definition of genus).at n=49A218538G.f. A(x) satisfies: x = Sum_{n=-oo..+oo} (-x)^n * (1 + A(x)*x^n)^n.at n=12A355869