g(k): smallest s such that every n = x_1^k + … + x_s^k. Hilbert 1909 existence; Hardy-Littlewood circle method; G(k) < g(k) uses fewer squares for large n.
g(k): smallest s such that every n = x_1^k + … + x_s^k. Hilbert 1909 existence; Hardy-Littlewood circle method; G(k) < g(k) uses fewer squares for large n.