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A163490
Least number k having n representations as the sum of the minimal number of cubes A002376(k).
0
1, 157, 221, 626, 894, 1488, 1489, 3020, 1912, 1938, 3685, 3659, 4982, 4369, 5279, 13127, 4882, 5305, 8042, 16116, 16620, 18884, 23604, 22514, 22542, 29094, 31353, 27660, 41388, 38883
OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Waring's Problem.
EXAMPLE
a(1) = 1 since 1 = 1^3 (1 way with minimal representation).
a(2) = 157 since 157 = 1^3 + 1^3 + 3^3 + 4^3 + 4^3 = 2^3 + 2^3 + 2^3 + 2^3 + 5^3 (2 ways with minimal representation).
a(3) = 221 since 221 = 1^3 + 1^3 + 1^3 + 1^3 + 1^3 + 6^3 = 1^3 + 1^3 + 3^3 + 4^3 + 4^3 + 4^3 = 2^3 + 2^3 + 2^3 + 2^3 + 4^3 + 5^3 (3 ways with minimal representation).
MATHEMATICA
t=Table[r=PowersRepresentations[n, 9, 3]; Sort[Tally[9-Count[#, 0]&/@r]][[1, 2]], {n, 1000}]; u=Union[t]; c=Complement[Range[Max[u]], u]; If[c=={}, mx=u[[-1]], mx=c[[1]]-1]; Flatten[Table[Position[t, n, 1, 1], {n, mx}]]
CROSSREFS
Cf. A002376.
Sequence in context: A236537 A048927 A343702 * A142063 A151739 A142231
KEYWORD
nonn,more
AUTHOR
Martin Renner, Jan 22 2011, Jan 25 2011
EXTENSIONS
a(16)-a(30) from Alois P. Heinz, Feb 10 2011
STATUS
approved