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Mathematics of Computation
Journal of the American Mathematical Society
ISSN 1088-6842(e) ISSN 0025-5718(p)
     

On searching for solutions of the Diophantine equation $x^3 + y^3 +z^3 = n$

Author(s): Kenji Koyama; Yukio Tsuruoka; Hiroshi Sekigawa.
Journal: Math. Comp. 66 (1997), 841-851.
MSC (1991): Primary 11D25
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Abstract: We propose a new search algorithm to solve the equation $x^3+y^3+z^3=n$ for a fixed value of $n>0$. By parametrizing $|x|=$min$(|x|, |y|, |z|)$, this algorithm obtains $|y|$ and $|z|$ (if they exist) by solving a quadratic equation derived from divisors of $|x|^3 \pm n$. By using several efficient number-theoretic sieves, the new algorithm is much faster on average than previous straightforward algorithms. We performed a computer search for 51 values of $n$ below 1000 (except $n\equiv \pm 4 (\MOD 9)$) for which no solution has previously been found. We found eight new integer solutions for $n=75,  435,  444,  501,  600,   618,  912,$ and $969$ in the range of $|x| \le 2 \cdot 10^7$.


References:

1.
A. Bremner, On sums of three cubes, Canadian Math. Soc. Conf. Proc. 15 (1995), 87-91. MR 96g:11024
2.
B. Conn and L. Vaserstein, On sums of three integral cubes, Contemp. Math. 166 (1994), 285-294. MR 95g:11128
3.
V. L. Gardiner, R. B. Lazarus and P. R. Stein, Solutions of the Diophantine equation $x^3+y^3=z^3-d$, Math. Comp. 18 (1964), 408-413. MR 31:119
4.
R. K. Guy, Unsolved Problems in Number Theory, First Edition, Springer, New York, 1981. MR 83k:10002
5.
R. K. Guy, Unsolved Problems in Number Theory, Second Edition, Springer, New York, 1994. MR 96e:11002
6.
D. R. Heath-Brown, W. M. Lioen and H. J. J. te Riele, On solving the Diophantine equation $x^3+y^3+z^3=k$ on a vector processor, Math. Comp. 61 (1993), 235-244. MR 94f:11132
7.
W. C. Jagy, Progress report, private communication, January 1995.
8.
K. Koyama, Tables of solutions of the Diophantine equation $x^3+y^3+z^3=n$, Math. Comp. 62 (1994), 941-942.
9.
K. Koyama, On the solutions of the Diophantine equation $x^3+y^3+z^3=n$, Trans. of Inst. of Electronics, Information and Communication Engineers (IEICE in Japan), Vol.E78-A, No. 3 (1995), 444-449.
10.
R. F. Lukes, A very fast electronic number sieve, Ph. D. Thesis, Univ. of Manitoba (1995).
11.
J. C. P. Miller and M. F. C. Woollett, Solutions of the Diophantine equation $x^3+y^3+z^3=k$, J. London Math. Soc. 30 (1955), 101-110. MR 16:797e
12.
L. J. Mordell, Diophantine Equations, Academic Press, New York, 1969. MR 40:2600
13.
H. J. J. te Riele and J. van de Lune, Computational number theory at CWI in 1979-1994, CWI Quarterly, Vol.7, No.4 (1994). MR 96g:11147
14.
H. Sekigawa and K. Koyama, Existence condition of solutions of congruence $x^n+y^n \equiv m   (\MOD  p^e)$, in preparation.
15.
W. Scarowsky and A. Boyarsky, A note on the Diophantine equation $x^n+y^n+z^n=3$, Math. Comp. 42 (1984), 235-237. MR 85c:11029


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Additional Information:

Kenji Koyama
Affiliation: NTT Communication Science Laboratories 2-2 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-02 Japan
Email: koyama@cslab.kecl.ntt.jp

Yukio Tsuruoka
Affiliation: NTT Communication Science Laboratories 2-2 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-02 Japan
Email: tsuruoka@cslab.kecl.ntt.jp

Hiroshi Sekigawa
Affiliation: NTT Communication Science Laboratories 2-2 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-02 Japan
Email: sekigawa@cslab.kecl.ntt.jp

DOI: 10.1090/S0025-5718-97-00830-2
PII: S 0025-5718(97)00830-2
Keywords: Diophantine equation, cubic, number-theoretic sieves, search algorithm, computer search
Received by editor(s): November 13, 1995
Received by editor(s) in revised form: February 14, 1996
Copyright of article: Copyright 1997, American Mathematical Society


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