Two spherical stars A and B have densities ρ_A and ρ_B, respectively. A and B have the same radius, and their masses M_A and M_B are related by M_B=2M_A. Star A loses mass so that its radius is halved while its density remains ρ_A. The entire mass lost by A is deposited as a thick spherical shell on B with density ρ_A. If v_A and v_B are the escape velocities after the interaction and v_B/v_A=√(10n/15^{1/3}), the value of n is _____.