A225526 Number of distinct products i*j over all pairs (i,j) with |i| + |j| <= n and gcd(i,j) <= 1.

1, 1, 3, 5, 7, 11, 13, 17, 21, 27, 31, 39, 43, 51, 57, 63, 69, 81, 87, 99, 107, 117, 125, 139, 147, 159, 169, 183, 195, 215, 223, 241, 257, 273, 287, 305, 315, 339, 353, 371, 383, 407, 419, 443, 461, 479, 497, 523, 539, 567, 585

Offset

0,3

Comments

This sequence is in reply to an extension request made in A100449.

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

Links

Robert Price, Table of n, a(n) for n = 0..400

Mathematica

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

Crossrefs

Cf. A018805, A027430, A100448, A100449, A100450, A213208.

Sequence in context: A309739 A249876 A096169 * A090670 A074832 A075794

Adjacent sequences: A225523 A225524 A225525 * A225527 A225528 A225529

Keyword

nonn,easy

Author

Robert Price, May 09 2013

Status

approved