A229848 Values of n such that the equation x^2 - 3*n*y^2 = n has integer solutions.

1, 4, 7, 9, 13, 16, 19, 25, 28, 31, 36, 37, 43, 49, 52, 61, 63, 64, 67, 76, 79, 81, 91, 100, 103, 109, 112, 117, 121, 124, 127, 139, 144, 148, 151, 157, 163, 169, 171, 172, 175, 181, 193, 196, 199, 208, 211, 217, 223, 225, 229, 244, 247, 252, 256, 268, 271

Offset: 1

Author

Colin Barker, Oct 07 2013

Keywords

• nonn

Examples

			37 appears in the sequence because the equation x^2 - 111*y^2 = 37 has integer solutions.
		

Crossrefs

Cf. A172000, A227939

Programs

Mathematica

Select[Range[300],Length[FullSimplify[Solve[x^2-3*#*y^2==#,{x,y},Integers]/.C[1]->1]]>0&] (* Vaclav Kotesovec, Oct 08 2013 *)