In this paper, we prove that infinite-dimensional vector spaces of -dense curves are generated by means of the functional equations f(x)+f(2x)+${cdots}$+f(nx) = 0, with $n{geq}2$, which are related to the partial sums of the Riemann zeta function. These curves ${alpha}$-densify a large class of compact sets of the plane for arbitrary small ${alpha}$, extending the known result that this holds for the cases n = 2, 3. Finally, we prove the existence of a family of solutions of such functional equation which has the property of quadrature in the compact that densifies, that is, the product of the length of the curve by the $n^{th}$ power of the density approaches the Jordan content of the compact set which the curve densifies.