Hyperelliptic Curves, Continued Fractions and Somos Sequences

I should point out that any actual expansion is very messy. I give the list
of partial quotients of two very different examples. First
p
X 4 − 2X 3 + 3X 2 + 2X + 1 + (X 2 − X + 1) =
[2(X 2 − X + 1) , 1 2 X − 1 2 , 2X − 2 , 1 2 X 2 − 1 2 X + 1 2 , 2X − 2 , 1 2 X − 1 2 ].
Here, I’ve copied the expansion of 2Z in a periodic case (so, there’s a
pseudo-elliptic integral with D = X 4 − 2X 3 + 3X 2 + 2X + 1). Note that
the quasi-period already supplies a unit. In fact
Z X 4t − 1
p t 4 − 2t 3 + 3t 2 + 2t + 1 dt =
log ` X 4 −3X 3 +5X 2 −2X
+(X 2 p
− 2X + 2) X 4 − 2X 3 + 3X 2 + 2X + 1 ´ .
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