A226601 Number of ordered triples (i,j,k) with i*j*k <= n, i,j,k >= 0 and gcd{i,j,k} <= 1.

1, 8, 17, 32, 50, 77, 98, 137, 170, 212, 245, 308, 350, 425, 470, 527, 587, 686, 740, 851, 917, 998, 1067, 1202, 1277, 1403, 1484, 1601, 1691, 1862, 1937, 2120, 2231, 2360, 2465, 2618, 2726, 2945, 3062, 3215, 3338, 3581, 3680, 3935, 4073, 4235, 4376, 4655

Offset

0,2

Comments

Note that gcd(0,m) = m for any m.

Links

Robert Price, Table of n, a(n) for n = 0..100

Mathematica

f[n_] := Length[Complement[Union[Flatten[Table[If[i*j*k <= n && GCD[i, j, k] ≤ 1, {i, j, k}], {i, 0, n}, {j, 0, n}, {k, 0, n}], 2]], {Null}]]; Table[f[n], {n, 0, 100}]

Crossrefs

Cf. A100450, A226357, A226359, A226600.

Sequence in context: A099358 A077222 A077221 * A106648 A209376 A159696

Adjacent sequences: A226598 A226599 A226600 * A226602 A226603 A226604

Keyword

nonn

Author

Robert Price, Jun 13 2013

Status

approved