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A023042
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Numbers w such that w^3 = x^3+y^3+z^3, x>y>z>=0, is soluble.
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2
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6, 9, 12, 18, 19, 20, 24, 25, 27, 28, 29, 30, 36, 38, 40, 41, 42, 44, 45, 46, 48, 50, 53, 54, 56, 57, 58, 60, 63, 66, 67, 69, 70, 71, 72, 75, 76, 78, 80, 81, 82, 84, 85, 87, 88, 89, 90, 92, 93, 95, 96, 97, 99, 100, 102, 103, 105, 106, 108, 110, 111, 112, 113, 114, 115, 116, 117
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OFFSET
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1,1
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COMMENTS
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Numbers whose cube is the sum of three nonnegative cubes.
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REFERENCES
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Ya. I. Perelman, Algebra can be fun, pp. 142-143.
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LINKS
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Table of n, a(n) for n=1..67.
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EXAMPLE
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20 belongs to the sequence as 20^3 = 7^3 + 14^3 + 17^3.
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MATHEMATICA
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lst={}; Do[Do[Do[Do[y=a^3+b^3+c^3; x=z^3; If[y<x, Break[], If[y==x, AppendTo[lst, z]]], {c, b-1, 0, -1}], {b, a-1, 0, -1}], {a, z-1, 0, -1}], {z, 2, 3*5!}]; Union@lst [From Vladimir Joseph Stephan Orlovsky, Apr 11 2010]
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CROSSREFS
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Cf. A001235, A114923.
Sequence in context: A020938 A136360 A023483 * A128245 A117714 A114554
Adjacent sequences: A023039 A023040 A023041 * A023043 A023044 A023045
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane.
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STATUS
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approved
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