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A051388 Numbers whose 4th power can be expressed as the sum of two positive cubes in more than one way. 1

%I

%S 1729,2457,4104,4914,4977,8001,8216,10773,13832,15561,16263,19656,

%T 20683,32832,39312,39816,40033,46683,64008,64232,65728,66339,80236,

%U 86184,110656,110808,124336,124488,127062,130104,132678,132867,134379,149389,157248,165464,166887,171288

%N Numbers whose 4th power can be expressed as the sum of two positive cubes in more than one way.

%e 1729^4 = 1729^3+20748^3 = 15561^3+17290^3

%o (PARI) for(i=1, 10^5, x=i^4; c=0; for(j=1, floor(sqrtn(x/2,3)), if(ispower(x-j^3,3), c++)); if(c>1, print(i" "c))) [From _Donovan Johnson_, Aug 03 2009]

%Y Cf. A051386, A051387.

%Y Cf. A226777, A226950.

%K nonn

%O 1,1

%A _Jud McCranie_

%E More terms from _John W. Layman_, Feb 24 2003

%E a(18)-a(24) from _Donovan Johnson_, Aug 03 2009

%E a(25)-a(38) from _Donovan Johnson_, Dec 03 2010

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Last modified August 31 02:32 EDT 2014. Contains 246235 sequences.