cp's OEIS Frontend

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

%I A163490 #31 Feb 16 2025 08:33:11
%S A163490 1,157,221,626,894,1488,1489,3020,1912,1938,3685,3659,4982,4369,5279,
%T A163490 13127,4882,5305,8042,16116,16620,18884,23604,22514,22542,29094,31353,
%U A163490 27660,41388,38883
%N A163490 Least number k having n representations as the sum of the minimal number of cubes A002376(k).
%H A163490 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/WaringsProblem.html">Waring's Problem</a>.
%e A163490 a(1) = 1 since 1 = 1^3 (1 way with minimal representation).
%e A163490 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).
%e A163490 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).
%t A163490 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}]]
%Y A163490 Cf. A002376.
%K A163490 nonn,more
%O A163490 1,2
%A A163490 _Martin Renner_, Jan 22 2011, Jan 25 2011
%E A163490 a(16)-a(30) from _Alois P. Heinz_, Feb 10 2011