A225523 Number of distinct products i*j over all pairs (i,j) with |i| + |j| <= n.

1, 1, 3, 5, 9, 11, 17, 21, 27, 33, 39, 43, 53, 59, 69, 79, 89, 97, 107, 117, 131, 143, 157, 167, 183, 195, 209, 223, 237, 249, 269, 283, 301, 317, 335, 353, 373, 389, 409, 427, 449, 465, 491, 509, 535, 557, 581, 603, 631, 657, 679

Offset: 0

Author

Robert Price, May 09 2013

Keywords

• nonn
• easy

Comments

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

Links

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

Crossrefs

Cf. A018805, A027430, A100448, A100449, A100450, A213207.

Programs

Mathematica

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