-319334400domain: ZAppears in sequencesA triangular sequence of coefficients based on an expansion of a Skew Catenoid of Matthius Weber like Sheffer expansion function: g(t) = x*(3 + t^2)/(t^2 - 1); f(t) = (3 + t^2)/(t^2 - 1); p(x,t) = Exp[x*(t)]*(1 - f(t)2).at n=29A137528