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For printing - MSP

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CONSTRUCTING FAMILIES OF LONG CONTINUED FRACTIONS 137<br />

If we then expand the continued fraction 2 w<br />

v<br />

2 w<br />

v = [b1; b2, . . . , bn]<br />

we can assume <br />

u v ′<br />

= [b1; b2, . . . , bm].<br />

2x w<br />

Then<br />

{b1; b2, . . . , bm, an; an−1, . . . , a1}<br />

<br />

u v ′ u 2v ′<br />

=<br />

=<br />

2x w x w<br />

u 2 + 2v ′2 xu + wv ′<br />

2(xu + wv ′ ) 2x 2 + w 2<br />

w and 2v .<br />

<strong>For</strong> an example, start with 1<br />

2 . This leads to the matrix product<br />

<br />

0 1 0 1 1 1<br />

{2, 1} =<br />

= ,<br />

1 2 1 1 2 3<br />

If v is odd, and w = 2w ′ , a similar trick works for w<br />

v<br />

and in turn to values set in Proposition 2:<br />

and<br />

ɛ = 1<br />

d = m 2 + 2r k =<br />

r = 7 + 6l<br />

Ai = ri − 1<br />

3<br />

Bi = 2Ai<br />

m = Ak + l<br />

(6l + 7) k + 3l − 1<br />

3<br />

2<br />

<br />

+ 2(6l + 7) k .<br />

Then<br />

<br />

(6l + 7) t − 1<br />

Nt =<br />

, 2, 1, 2<br />

3<br />

(6l + 7)k−1−t <br />

− 1<br />

3<br />

gives<br />

<br />

(6l <br />

+ 7) k 2<br />

+ 3l − 1<br />

+ 2(6l + 7)<br />

3<br />

k<br />

=<br />

<br />

m, −→<br />

N0, −→<br />

N1, . . . , −→<br />

N k−1, m, ←<br />

After the zeros are removed, this is<br />

N k−1<br />

←<br />

N k−2, . . . , ←<br />

.<br />

<br />

N1, 2m .

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