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Conference rusure::math

Title:Mathematics at DEC
Moderator:RUSURE::EDP
Created:Mon Feb 03 1986
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2083
Total number of notes:14613

112.0. "Triples w same sum & product" by HARE::STAN () Tue Jul 31 1984 19:12

J. G. Mauldon asks how many different triples of positive integers
can you have with the same sum and the same product.
The best anyone has been able to come up with is 5 triples:

( 6, 480, 495)
(11, 160, 810)
(12, 144, 825)
(20,  81, 880)
(33,  48, 900)

Can anyone find 6 such triples?

	Reference

Richard K. Guy, Unsolved Problems in Number Theory, Springer-Verlag,
	New York: 1981. Page 96, problem D16.
T.RTitleUserPersonal
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112.1TOOLS::STANSat May 25 1985 20:0728
What! No one has bettered the record? Shame.

Lorraine Foster and Gabriel Robins "using a modest computer and various
memory sparing techniques" have found 10 triples that have sum
1326000 and product 2^7 3^6 5^4 7^2 13^3 17^3.

Their 10 triples are:

 83300	495720	746980
 79968	573750	672282
 80325	560235	685440
143325	224640	958035
139230	232050	954720
119340	278460	928200
106080	324870	895050
 92820	397800	835380
 89505	424320	812175
 79560	596700	649740

Consult the follwing reference for the algorithm used:

			Reference
			---------
Lorraine Foster and Gabriel Robins, Solution to Problem E2872.
	American Mathematical Monthly. 89(1982)499-500.

Now with a powerful computer and lots of "memory sparing techniques",
someone should be able to do better than this!