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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

1787.0. "College Mathematics Journal #509" by RUSURE::EDP (Always mount a scratch monkey.) Fri Sep 10 1993 14:26

    Proposed by Norman Schaumberger, Hofstra University, Hempstead, NY.
    
    Prove or disprove that, for each positive integer n, the diophantine
    equation
    
    	x^n + y^(n+1) + z^(n+2) + w^(n+3) = v^(n^2+3n+1)
    
    has a solution in positive integers.
T.RTitleUserPersonal
Name
DateLines
1787.1CSC32::D_DERAMODan D'Eramo, Customer Support CenterSat Sep 11 1993 22:3019
        Let
        
        	P = n(n+1)(n+2)(n+3)
        	x = 4^(P/n)
        	y = 4^(P/(n+1))
        	z = 4^(P/(n+2))
        	w = 4^(P/(n+3))
        
        Then the left hand side is 4(4^P) = 4^(P+1) which is
        4^(n^4 + 6n^3 + 11n^2 + 6n + 1) = 4^((n^2 + 3n + 1)(n^2 + 3n + 1))
        = (4^(n^2 + 3n + 1))^(n^2 + 3n + 1).  So you can combine the
        above with
        
        	v = 4^(n^2 + 3n + 1)
        
        to get a solution in positive integers for any positive
        integer n.
        
        Dan