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A018889
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Shortest representation as sum of positive cubes requires exactly 8 cubes.
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9
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15, 22, 50, 114, 167, 175, 186, 212, 231, 238, 303, 364, 420, 428, 454
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OFFSET
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1,1
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COMMENTS
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Wieferich proved that 167 is the unique prime in this sequence. - Jonathan Vos Post, Sep 23 2006
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REFERENCES
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Joe Roberts, Lure of the Integers, entry 239.
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LINKS
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Table of n, a(n) for n=1..15.
Jan Bohman and Carl-Erik Froberg, Numerical investigation of Waring's problem for cubes, Nordisk Tidskr. Informationsbehandling (BIT) 21 (1981), 118-122.
G. L. Honaker, Jr. and Chris Caldwell, et al., A Prime Curios Page.
K. S. McCurley, An effective seven-cube theorem, J. Number Theory, 19 (1984), 176-183.
Eric Weisstein's World of Mathematics, Cubic Number
Eric Weisstein's World of Mathematics, Warings Problem
Index entries for sequences related to sums of cubes
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MATHEMATICA
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max = 500; nn = Union[(#*#).# & /@ Tuples[Range[0, 7], {7}]][[1 ;; max]]; Select[{#, PowersRepresentations[#, 8, 3]} & /@ Complement[Range[max], nn] , #[[2]] != {} &][[All, 1]] (* Jean-François Alcover, Jul 21 2011 *)
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CROSSREFS
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Subsequence of A018888.
Sequence in context: A006615 A114867 A109288 * A186525 A236107 A065728
Adjacent sequences: A018886 A018887 A018888 * A018890 A018891 A018892
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KEYWORD
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nonn,fini,full,nice
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AUTHOR
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Anon
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EXTENSIONS
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Corrected by Arlin Anderson (starship1(AT)gmail.com).
Additional comments from Jud McCranie.
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STATUS
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approved
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