login
Number of distinct sums i^3 + j^3 + k^3 for 0<=i<=j<=k<=n.
2

%I #13 Jul 17 2024 09:55:04

%S 1,4,10,20,35,56,82,117,162,215,279,352,426,528,645,772,899,1057,1235,

%T 1429,1647,1883,2133,2415,2694,3022,3374,3721,4130,4564,5011,5503,

%U 5986,6531,7045,7664,8273,8945,9659,10383,11127,11949,12809,13713,14649,15633,16644,17715,18735,19916

%N Number of distinct sums i^3 + j^3 + k^3 for 0<=i<=j<=k<=n.

%o (PARI) a(n) = my(v=vector(3*n^3+1)); for(i=0, n, for(j=i, n, for(k=j, n, v[i^3+j^3+k^3+1]+=1))); sum(i=1, #v, v[i]>0);

%Y Cf. A374707, A374711.

%Y Cf. A034966.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Jul 17 2024