181786domain: NAppears in sequencesLet r, s, t, u be four permutations of the set { 1, 2, 3, ..., n }; a(n) = minimal value of Sum_{i=1..n} r(i)*s(i)*t(i)*u(i).at n=22A070736Number of strings of numbers x(i=1..6) in 0..n with sum i^2*x(i) equal to n*36.at n=22A183957