-123849domain: ZAppears in sequencesE.g.f.: z*(((exp(z)+1)/((exp(z)+2*exp(-z/2)*cos(z*sqrt(3)/2))/3))-1).at n=11A281586Triangle read by rows, expansion of exp(x*z)*z*((exp(z) + 1)/((exp(z) + 2*exp(-z/2)*cos(z*sqrt(3)/2))/3) -1), for n >= 1 and 0 <= k <= n-1.at n=55A294034