The modular curve $X_{221}$

Curve name $X_{221}$
Index $48$
Level $16$
Genus $0$
Does the subgroup contain $-I$? Yes
Generating matrices $ \left[ \begin{matrix} 15 & 14 \\ 0 & 3 \end{matrix}\right], \left[ \begin{matrix} 3 & 0 \\ 12 & 3 \end{matrix}\right], \left[ \begin{matrix} 9 & 11 \\ 0 & 3 \end{matrix}\right], \left[ \begin{matrix} 3 & 0 \\ 0 & 3 \end{matrix}\right]$
Images in lower levels
LevelIndex of imageCorresponding curve
$2$ $3$ $X_{6}$
$4$ $12$ $X_{27}$
$8$ $24$ $X_{95}$
Meaning/Special name
Chosen covering $X_{95}$
Curves that $X_{221}$ minimally covers $X_{95}$, $X_{105}$, $X_{106}$
Curves that minimally cover $X_{221}$ $X_{221a}$, $X_{221b}$, $X_{221c}$, $X_{221d}$
Curves that minimally cover $X_{221}$ and have infinitely many rational points. $X_{221a}$, $X_{221b}$, $X_{221c}$, $X_{221d}$
Model \[\mathbb{P}^{1}, \mathbb{Q}(X_{221}) = \mathbb{Q}(f_{221}), f_{95} = f_{221}^{2}\]
Info about rational points None
Comments on finding rational points None
Elliptic curve whose $2$-adic image is the subgroup $y^2 + xy = x^3 - x^2 - 6x + 377$, with conductor $153$
Generic density of odd order reductions $9249/57344$

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