The modular curve $X_{57}$

Curve name $X_{57}$
Index $16$
Level $16$
Genus $0$
Does the subgroup contain $-I$? Yes
Generating matrices $ \left[ \begin{matrix} 1 & 7 \\ 1 & 2 \end{matrix}\right], \left[ \begin{matrix} 15 & 11 \\ 0 & 1 \end{matrix}\right]$
Images in lower levels
LevelIndex of imageCorresponding curve
$2$ $1$ $X_{1}$
$4$ $4$ $X_{7}$
$8$ $8$ $X_{22}$
Meaning/Special name
Chosen covering $X_{22}$
Curves that $X_{57}$ minimally covers $X_{22}$
Curves that minimally cover $X_{57}$ $X_{370}$, $X_{440}$, $X_{57a}$, $X_{57b}$
Curves that minimally cover $X_{57}$ and have infinitely many rational points. $X_{57a}$, $X_{57b}$
Model \[\mathbb{P}^{1}, \mathbb{Q}(X_{57}) = \mathbb{Q}(f_{57}), f_{22} = \frac{3f_{57}^{2} + 6f_{57} - 3}{f_{57}^{2} + 1}\]
Info about rational points None
Comments on finding rational points None
Elliptic curve whose $2$-adic image is the subgroup $y^2 = x^3 + x^2 - 13x + 43$, with conductor $6400$
Generic density of odd order reductions $91681/172032$

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