Cn(x)=2Tn(x/2)

Sn(x)=Un(x/2)

x^2-Dy^2=4．

最小解(x1,y1)

fn=x1fn-1-fn-2

xn=Cn(x1),yn=y1Sn-1(x1)

xn=C~2n(t1),yn=u1S~2n-1(t1)

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x^2-Dy^2=-4．

最小解(r1,s1)

fn=x1fn-1-fn-2

rn=C~2n-1(r1),sn=s1S~2n-2(r1)

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x^2-Dy^2=+/-4．

最小解(t1,u1)

fn=t1fn-1+fn-2

tn=C~n(t1),un=u1S~n-1(t1)

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