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Euler was wrong (Posted on 2022-07-06) Difficulty: 4 of 5
The great Euler conjected, inter alia, that at least n powers of positive integers are needed to get a sum which is a n-th power as well.
It is up to you to find a set of integers {a,b,c,d,e} such that a^5+b^5+c^5+d^5=e^5.

REM: If unable to provide a proof, present the current state of known solutions for 4th and 5th powers. AFAIK no solution for the 6th power exists so far.

See The Solution Submitted by Ady TZIDON    
Rating: 5.0000 (1 votes)

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Solution Current State of Known Solutions for 4th and 5th Powers | Comment 2 of 3 |
WIKIPEDIA, in the article "Euler's Sum of Powers Conjecture" says:
"Euler's conjecture was disproven by L.J. Lander and T.R. Parkin in 1966 when, through a direct computer search on a CDC 6600, they found a counterexample for k=5 (fifth power case). This was published in a paper comprising just two sentences, 
A total of three primitive (that is, in which the summands do NOT all have a common factor) counterexample are known:
--> 27^5+ 84^5+110^5+133^5=144^5 (Lander and Parkin, 1966)
--> (-220)^5+ 5027^5 + 6237^5+14068^5 = 14132^5 ( Scher and Seidl, 1996)
--> 55^5 + 3183^5+ 28969^5+85282^5 =85359^5 (Frye, 2004)

        In 1988, Noam Elkies published a method to construct an infinite sequence of counter examples for the k=4 case. His smallest counterexample was:
2682440^4 + 15365639^4 + 18796760^4 =20615673^4
 A particular case of Elkies' solution can be reduced to the identity:
 (85v^2+484v-313)^4 +(68v^2 -586v+10)^4+ (2u)^4 = (357v^2 - 204v+363)^4
where, u^2= 22030 +28849v -56158v^2+36941v^3-31790v^4.
This is an elliptic curve with rational point at v_1 = -31/467. From this initial rational point, one can compute an infinite collection of others, Substituting v_1 into the identity and removing common factors gives the numerical example cited above.
           In 1988, Roger Frye found the smallest possible counterexample 
95800^4 + 217519^4 + 414560^4 = 422481^4
for k=4 by a direct computer search using techniques suggested by Elkies.This solution is the only one with the values of the variable below 1,000,000."

Edited on July 6, 2022, 11:22 pm
  Posted by K Sengupta on 2022-07-06 21:32:58

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