A163490 Least number k having n representations as the sum of the minimal number of cubes A002376(k).

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

Table of n, a(n) for n=1..30.

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

Adjacent sequences: A163487 A163488 A163489 * A163491 A163492 A163493

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