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A057903
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Positive integers that are not the sum of exactly two positive cubes.
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2
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1, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79
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OFFSET
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1,2
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COMMENTS
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Includes the cubes themselves (since a^3 = b^3 + c^3 has no solution, by the exponent 3 case of Fermat's Last Theorem), so is different from A022555.
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LINKS
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FORMULA
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MATHEMATICA
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pr[n_] := Select[ PowersRepresentations[n, 2, 3], FreeQ[#, 0]& ]; Select[ Range[80], pr[#] == {} &] (* Jean-François Alcover, Nov 08 2012 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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