This site is supported by donations to The OEIS Foundation.

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A051388 Numbers whose 4th power can be expressed as the sum of two positive cubes in more than one way. 2

%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.

%H Chai Wah Wu, <a href="/A051388/b051388.txt">Table of n, a(n) for n = 1..358</a>

%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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 7 14:52 EST 2016. Contains 278877 sequences.