Higher moment of coefficients of Dedekind zeta function

Let K3 be a non-normal cubic extension over ℚ:We study the higher moment of the coefficients $${a_{{K_3}}}(n)$$ of Dedekind zeta function over sum of two squares $$\sum\nolimits_{n_1^2 + n_2^2 \leqslant x} {a_{{K_3}}^l(n_1^2 + n_2^2)} $$ where 2 ⩽ l ⩽ 8 and n1; n2; l∈ ℤ.