Project supported by the National Natural Science Foundation of China.
Let r(n) denote the number of representations of n as the sums of 5 cubes and 3 biquadra-tes of natural numbers. Then for all sufficiently large n, one has r(n)(?)n17/12, which is the expected order of magnitude of r(n).
Project supported by the National Natural science Foundation of China
It is shown that almost all natural numbers can be expressed as the sum of three cubes aud one fifth power of natural numbers. To be more precise, we have E(N)<