OFFSET
1,1
EXAMPLE
a(7)=11 because d=11 is the smallest d giving integer solutions x=2,y=1 in
(2*7+1)= x^2+d*y^2 = 2^2 + 11* 1^2 = 15.
MATHEMATICA
<< NumberTheory`NumberTheoryFunctions`; Table[First@Select[Range[100], !MatchQ[t=QuadraticRepresentation[ #, 2n+1], _QuadraticRepresentation]&, 1], {n, 1, 128}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Wouter Meeussen, Jun 20 2003
STATUS
approved