The modular curve $X_{211s}$

Curve name $X_{211s}$
Index $96$
Level $16$
Genus $0$
Does the subgroup contain $-I$? No
Generating matrices $ \left[ \begin{matrix} 5 & 5 \\ 0 & 5 \end{matrix}\right], \left[ \begin{matrix} 9 & 0 \\ 0 & 1 \end{matrix}\right], \left[ \begin{matrix} 5 & 5 \\ 0 & 1 \end{matrix}\right], \left[ \begin{matrix} 15 & 0 \\ 8 & 1 \end{matrix}\right]$
Images in lower levels
LevelIndex of imageCorresponding curve
$2$ $3$ $X_{6}$
$4$ $12$ $X_{13h}$
$8$ $48$ $X_{85k}$
Meaning/Special name
Chosen covering $X_{211}$
Curves that $X_{211s}$ minimally covers
Curves that minimally cover $X_{211s}$
Curves that minimally cover $X_{211s}$ and have infinitely many rational points.
Model $\mathbb{P}^{1}$, a universal elliptic curve over an appropriate base is given by \[y^2 = x^3 + A(t)x + B(t), \text{ where}\] \[A(t) = -27t^{16} - 12960t^{15} - 232416t^{14} - 1088640t^{13} - 1975104t^{12} + 1451520t^{11} + 5377536t^{10} + 22394880t^{9} + 48176640t^{8} - 89579520t^{7} + 86040576t^{6} - 92897280t^{5} - 505626624t^{4} + 1114767360t^{3} - 951975936t^{2} + 212336640t - 1769472\] \[B(t) = -54t^{24} + 54432t^{23} + 3595104t^{22} + 50730624t^{21} + 316540224t^{20} + 838688256t^{19} + 733404672t^{18} - 2414168064t^{17} - 12561246720t^{16} - 20149420032t^{15} - 16335323136t^{14} - 1226244096t^{13} + 268429787136t^{12} + 4904976384t^{11} - 261365170176t^{10} + 1289562882048t^{9} - 3215679160320t^{8} + 2472108097536t^{7} + 3004025536512t^{6} - 13741068386304t^{5} + 20744780120064t^{4} - 13298728697856t^{3} + 3769739771904t^{2} - 228304355328t - 905969664\]
Info about rational points
Comments on finding rational points None
Elliptic curve whose $2$-adic image is the subgroup $y^2 = x^3 - x^2 - 30732800x + 65587209600$, with conductor $1680$
Generic density of odd order reductions $19/336$

Back to the 2-adic image homepage.