Abstract. We study Liouville theorems for the following polyharmonic Hénon-Lane-Emden systemwhen m, p, q ≥ 1, pq = 1, a, b ≥ 0. The main conjecture states that (u, v) = (0, 0) is the unique nonnegative solution of this system whenever (p, q) is under the critical Sobolev hyperbola, i.e. > n − 2m. We show that this is indeed the case in dimension n = 2m + 1 for bounded solutions. In particular, when a = b and p = q, this means that u = 0 is the only nonnegative bounded solution of the polyharmonic Hénon equationin dimension n = 2m + 1 provided p is the subcritical Sobolev exponent, i.e., 1 < p < 1 + 4m + 2a.Moreover, we show that the conjecture holds for radial solutions in any dimensions. It seems the power weight functions |x| a and |x| b make the problem dramatically more challenging when dealing with nonradial solutions.