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A066890
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Cubes that are the sum of three distinct positive cubes.
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1
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216, 729, 1728, 5832, 6859, 8000, 13824, 15625, 19683, 21952, 24389, 27000, 46656, 54872, 64000, 68921, 74088, 85184, 91125, 97336, 110592, 125000, 148877, 157464, 175616, 185193, 195112, 216000, 250047, 287496, 300763, 328509, 343000, 357911, 373248, 421875
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OFFSET
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1,1
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REFERENCES
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David Wells, The Penguin Dictionary of Curious and Interesting Numbers (Rev. ed. 1997), pp. 130, 147
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LINKS
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Donovan Johnson, Table of n, a(n) for n = 1..1000
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FORMULA
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a(n) = (A023042(n))^3. - Christian N. K. Anderson, Aug 10 2014
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EXAMPLE
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729 is included because it is 9^3 and 1^3 + 6^3 + 8^3 = 729.
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MATHEMATICA
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maxCube = (m = 67)^3; Reap[ Do[ bmax = (maxCube - a^3)^(1/3) // Ceiling; Do[ cmax = (maxCube - b^3)^(1/3) // Ceiling; Do[ n = a^3 + b^3 + c^3; If[n <= maxCube, If[ IntegerQ[n^(1/3)], Sow[n]]], {c, b, cmax}], {b, a, bmax}], {a, 1, (maxCube - 2)^(1/3) // Ceiling}]][[2, 1]] // Flatten // Union (* Jean-François Alcover, Mar 07 2013 *)
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CROSSREFS
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Sequence in context: A043371 A074266 A208089 * A242296 A223507 A135590
Adjacent sequences: A066887 A066888 A066889 * A066891 A066892 A066893
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KEYWORD
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nonn
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AUTHOR
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Harvey P. Dale, Jan 22 2002
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EXTENSIONS
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Offset corrected by Arkadiusz Wesolowski, Aug 06 2012
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STATUS
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approved
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