211579212domain: NAppears in sequencesSum of the coefficients in the Schur expansion of Product_{1<=i<=j<=n} (1+x_i+x_j), which is the total Chern class for the vector bundle Sym^2(E) where E is a vector bundle over a smooth complex projective variety of rank n with Chern roots x_1,...,x_n.at n=6A306397