A374713 Number of distinct sums i^3 + j^3 + k^3 for 1<=i<=j<=k<=n.

1, 4, 10, 20, 35, 55, 83, 119, 164, 218, 280, 343, 431, 535, 648, 760, 903, 1064, 1241, 1442, 1659, 1891, 2151, 2409, 2714, 3044, 3369, 3754, 4160, 4582, 5044, 5499, 6015, 6500, 7094, 7669, 8308, 8990, 9683, 10394, 11180, 12010, 12876, 13773, 14720, 15693, 16721, 17705, 18845, 20010

Offset: 1

Author

Seiichi Manyama, Jul 17 2024

Keywords

• nonn

Crossrefs

Cf. A061791, A374714.

Cf. A374715.

Programs

PARI

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