The modular curve $X_{25n}$

Curve name $X_{25n}$
Index $24$
Level $4$
Genus $0$
Does the subgroup contain $-I$? No
Generating matrices $ \left[ \begin{matrix} 3 & 0 \\ 0 & 1 \end{matrix}\right], \left[ \begin{matrix} 1 & 2 \\ 0 & 1 \end{matrix}\right]$
Images in lower levels
LevelIndex of imageCorresponding curve
$2$ $6$ $X_{8}$
Meaning/Special name $X_1(2,4)$
Chosen covering $X_{25}$
Curves that $X_{25n}$ minimally covers
Curves that minimally cover $X_{25n}$
Curves that minimally cover $X_{25n}$ and have infinitely many rational points.
Model $\mathbb{P}^{1}$, a universal elliptic curve over an appropriate base is given by \[y^2 = x^3 + A(t)x + B(t), \text{ where}\] \[A(t) = -27t^{4} + 27t^{2} - 27\] \[B(t) = 54t^{6} - 81t^{4} - 81t^{2} + 54\]
Info about rational points
Comments on finding rational points None
Elliptic curve whose $2$-adic image is the subgroup $y^2 + xy + y = x^3 + x^2 - 39x + 36$, with conductor $231$
Generic density of odd order reductions $1/14$

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