A225523 - OEIS

%I #7 May 10 2013 12:25:28

%S 1,1,3,5,9,11,17,21,27,33,39,43,53,59,69,79,89,97,107,117,131,143,157,

%T 167,183,195,209,223,237,249,269,283,301,317,335,353,373,389,409,427,

%U 449,465,491,509,535,557,581,603,631,657,679

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

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

%H Robert Price, <a href="/A225523/b225523.txt">Table of n, a(n) for n = 0..400</a>

%t 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}]

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

%K nonn,easy

%O 0,3

%A _Robert Price_, May 09 2013