OFFSET
1,3
COMMENTS
Also numbers that are squarefree and primitively represented by x^2+x*y+y^2. - Frank M Jackson, Nov 08 2013
MATHEMATICA
lst = {}; Do[k=x^2+x*y+y^2; If[(SquareFreeQ[k] && GCD[x, y]==1) || k==0, AppendTo[lst, k]], {x, 0, 100}, {y, 0, x}]; Union@lst (* Frank M Jackson, Nov 08 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended by Ray Chandler, Jan 29 2009
STATUS
approved