2248575domain: NAppears in sequencesNumber of ordered solutions to x+y+z = u+v+w, 0 <= x, y, z, u, v, w < n.at n=20A071816Number of arrays of 6 integers in -n..n with sum zero.at n=10A201553Number of arrays of n integers in -10..10 with sum zero.at n=6A322540a(n) = Sum_{k=0..n} binomial(k+5,5) * binomial(k,n-k)^2.at n=10A377153