A226600 Number of ordered triples (i,j,k) with i*j*k <= n and i,j,k >= 0.

1, 8, 23, 44, 74, 107, 152, 197, 255, 315, 384, 453, 543, 624, 717, 816, 927, 1032, 1158, 1275, 1413, 1548, 1689, 1830, 2004, 2160, 2325, 2497, 2683, 2860, 3067, 3256, 3469, 3676, 3889, 4108, 4360, 4585, 4822, 5065, 5335, 5584, 5863, 6124, 6406, 6694, 6979

Offset: 0

Author

Robert Price, Jun 13 2013

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..5000 (terms n = 0..100 from Robert Price)

Crossrefs

Cf. A100450, A226357, A226359.

Programs

Mathematica

f[n_] := Length[Complement[Union[Flatten[Table[If[i*j*k <= n, {i, j, k}], {i, 0, n}, {j, 0, n}, {k, 0, n}], 2]], {Null}]]; Table[f[n], {n, 0, 100}]

Formula

a(n) = A003215(n) + A061201(n). - Alois P. Heinz, Jun 13 2013