-73306800domain: ZAppears in sequencesTriangle read by rows: expansion of p(x,t) = b(x,t)*u(x,t)*h(x,t) where b(x,t) = t*exp(x*t)/(exp(t)-1), u(x,t) = 1/(1-2*x*t+t^2), and h(x,t) = exp(2*x*t-t^2).at n=18A137981