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

1729, 2457, 4104, 4914, 4977, 8001, 8216, 10773, 13832, 15561, 16263, 19656, 20683, 32832, 39312, 39816, 40033, 46683, 64008, 64232, 65728, 66339, 80236, 86184, 110656, 110808, 124336, 124488, 127062, 130104, 132678, 132867, 134379, 149389, 157248, 165464, 166887, 171288

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..358

Example

1729^4 = 1729^3 + 20748^3 = 15561^3 + 17290^3.

Prog

(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))) \\ Donovan Johnson, Aug 03 2009

Crossrefs

Cf. A051386, A051387.

Cf. A226777, A226950.

Sequence in context: A288153 A154717 A306478 * A033181 A300949 A198775

Adjacent sequences: A051385 A051386 A051387 * A051389 A051390 A051391

Keyword

nonn

Author

Jud McCranie

Extensions

More terms from John W. Layman, Feb 24 2003

a(18)-a(24) from Donovan Johnson, Aug 03 2009

a(25)-a(38) from Donovan Johnson, Dec 03 2010

Status

approved