x^2-Dy^2=1．

最小解(x1,y1)

fn=2x1fn-1-fn-2

xn=Tn(x1),yn=y1Un-1(x1)

xn=T~2n(t1),yn=u1U~2n-1(t1)

＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝

x^2-Dy^2=-1．

最小解(r1,s1)

fn=2x1fn-1-fn-2

rn=T~2n-1(r1),sn=s1U~2n-1(r1)

＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝

x^2-Dy^2=+/-1．

最小解(t1,u1)

fn=2r1fn-1+fn-2

tn=T~n(t1),un=u1U~n-1(t1)

＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝