Computations concerning Waring's problem for cubes

Calcolo - Tập 19 - Trang 415-431 - 1982
F. Romani1
1Istituto di Elaborazione dell'Informazione, CNR-Pisa, Pisa

Tóm tắt

Waring's problem for cubes is investigated using numerical computations. The densities of number not representable as a sum of four and five cubes are computed in large intervals. Extrapolation of these data allows us to conjecture on the order of magnitude of last exceptions. The representability with four relative cubes and the validity of the theoretical asymptotic formula are investigated too. All the results reasonably confirm the conjecture that four relative cubes suffice to represent any integer and four nonnegative cubes suffice to represent any «large» integer.

Tài liệu tham khảo

J. Bohman—C. E. Froberg,Numerical Investigation of Waring's problem for Cubes, Bit, 21 (1981), 118–122. H. Davenport,On Waring's Problem for Cubes. Acta Math.71 (1939), 123–143. L. E. Dickson,All Integers Except 23 and 239 are Sum of Eight Cubes. Bull. Amer. Math. Soc.45 (1939), 588–591. W. J. Ellison,Waring's Problem. Amer. Math. Monthly.78 (1971), 10–36. L. Gatteschi,Funzioni Speciali. (1973). UTET, Torino. G. H. Hardy—J. E. Littlewood,Papers on Waring's Problem. (1966). In Collected works of G. H. Hardy, Oxford University Press,I, 377–506. L. K. Hua,On Waring's Problem. Quart. J.9 (1938), 199–202. E. Landau,Vorlesungen uber Zahlentheorie, VI teil: Das Waringsche Problem. (1969), Chelsea, New York. 235–360. L. J. Mordell,On the Representatio of an Integer as Sum of Four Integer Cubes. (1971), In Atkins et al. ed. «Computers in Number Theory», Academic Press. 115–118. I. M. Vinogradov,The Method of Trigonometric Sums in the Theory of Numbers. (1954). Interscience, London. G. L. Watson,A Proof of Seven Cube Theorem, J. London Math. Soc.26 (1951), 153–159. A. E. Western,Numbers Representable by Four or Five Cubes. J. London Math. Soc.1 (1926), 244–250.