\\ product of Eisenstein integers prd(u,v) = { (real(u)*real(v) - imag(u)*imag(v)) + (imag(u)*real(v)+real(u)*imag(v)-imag(u)*imag(v))*I; } \\ powers of 1+w z = 1 p1w = vector(6, k, [z, z=prd(z, 1+I)][1]) g(d) = { if (d==0, 0, my (u=(d-1)%2, v=(d-1)\2); (1+u) * p1w[1+v] ); } a(n) = { my (d=Vecrev(digits(n, 13)), p=1, z=0); for (k=1, #d, z+=prd(g(d[k]), p); p=prd(p, 4+I); ); real(z) } { for (n=0, 13^3-1, print (n " " a(n)); ); } quit