A227939 Values of n such that the equation x^2 - 2*n*y^2 = n has integer solutions.

1, 3, 4, 9, 11, 12, 16, 19, 25, 27, 33, 36, 43, 44, 48, 49, 51, 57, 59, 64, 67, 73, 75, 76, 81, 83, 89, 99, 100, 107, 108, 121, 123, 129, 131, 132, 139, 144, 147, 163, 169, 171, 172, 176, 177, 179, 187, 192

Offset: 1

Author

Colin Barker, Oct 07 2013

Keywords

• nonn

Examples

			59 appears in the sequence because the equation x^2 - 118*y^2 = 59 has integer solutions.
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..440

Crossrefs

Cf. A172000, A229848

Programs

Mathematica

Select[Range[200],Length[FullSimplify[Solve[x^2-2*#*y^2==#,{x,y},Integers]/.C[1]->1]]>0&] (* Vaclav Kotesovec, Oct 08 2013 *)