1194102domain: NAppears in sequencesa(n) = (1/4!)*3^(n+2)*(n+7)*(n+2)*(n+1)*(n).at n=5A288838Triangle (sans apex) of coefficients of terms of the form (eM_1)^j*(eM_2)^k re construction of triangle A287768.at n=48A288842a(n) = Sum_{-n <= a, b, c <= n} (b^2 - 4*a*c).at n=12A385029