A051386 -id:A051386 - cp's OEIS frontend

A051387 Numbers whose 4th power is the sum of two positive cubes in a nontrivial way.

134, 182, 183, 201, 219, 273, 278, 309, 399, 422, 453, 497, 579, 651, 658, 1036, 1132, 1324, 1464, 1482, 1554, 1608, 1612, 1752, 1842, 1996, 2058, 2184, 2457, 2472, 2476, 2483, 2574, 2634, 2994, 3052, 3192, 3465, 3474, 3618, 3624, 3724, 3858, 3906, 3976

Offset: 1

Jud McCranie

nonn

When x is the sum of 2 positive cubes (A003325) there is a trivial solution.
From Chai Wah Wu, Feb 23 2017: (Start)
2457, 4914, 4977, 8001, 8216, ... are terms that are also in A003325.
10202696, 29791125, 48137544, ... are terms that are also in A001235. (End)

			273^4 = 728^3 + 1729^3.

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Cf. A001235, A003325, A051386.

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

Original entry on oeis.org

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

Jud McCranie

nonn

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

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

Cf. A051386, A051387.

Cf. A226777, A226950.

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

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

cp's OEIS Frontend

A051387 Numbers whose 4th power is the sum of two positive cubes in a nontrivial way.

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