The modular curve $X_{211a}$

Curve name $X_{211a}$
Index $96$
Level $16$
Genus $0$
Does the subgroup contain $-I$? No
Generating matrices $ \left[ \begin{matrix} 7 & 0 \\ 8 & 1 \end{matrix}\right], \left[ \begin{matrix} 11 & 11 \\ 8 & 5 \end{matrix}\right], \left[ \begin{matrix} 1 & 0 \\ 8 & 7 \end{matrix}\right], \left[ \begin{matrix} 11 & 11 \\ 8 & 1 \end{matrix}\right]$
Images in lower levels
LevelIndex of imageCorresponding curve
$2$ $3$ $X_{6}$
$4$ $6$ $X_{13}$
$8$ $24$ $X_{85}$
Meaning/Special name
Chosen covering $X_{211}$
Curves that $X_{211a}$ minimally covers
Curves that minimally cover $X_{211a}$
Curves that minimally cover $X_{211a}$ and have infinitely many rational points.
Model $\mathbb{P}^{1}$, a universal elliptic curve over an appropriate base is given by \[y^2 = x^3 + A(t)x + B(t), \text{ where}\] \[A(t) = -108t^{26} - 52704t^{25} - 1346112t^{24} - 12624768t^{23} - 59280768t^{22} - 161782272t^{21} - 280433664t^{20} - 210511872t^{19} + 1026763776t^{18} + 4221517824t^{17} + 4718297088t^{16} + 13078167552t^{15} - 3409772544t^{14} - 52312670208t^{13} + 75492753408t^{12} - 270177140736t^{11} + 262851526656t^{10} + 215564156928t^{9} - 1148656287744t^{8} + 2650640744448t^{7} - 3885024411648t^{6} + 3309507182592t^{5} - 1411500736512t^{4} + 221056598016t^{3} - 1811939328t^{2}\] \[B(t) = 432t^{39} - 430272t^{38} - 33965568t^{37} - 771828480t^{36} - 8831607552t^{35} - 59945287680t^{34} - 263218249728t^{33} - 804177248256t^{32} - 1708217745408t^{31} - 1631653134336t^{30} + 4031911821312t^{29} + 22897894883328t^{28} + 64224805257216t^{27} + 95590557941760t^{26} + 44811864244224t^{25} - 112684506808320t^{24} - 874052862345216t^{23} - 1037364029816832t^{22} - 4149456119267328t^{20} + 13984845797523456t^{19} - 7211808435732480t^{18} - 11471837246521344t^{17} + 97884731332362240t^{16} - 263064802333556736t^{15} + 375159109768445952t^{14} - 264235373121503232t^{13} - 427728079247376384t^{12} + 1791196130608939008t^{11} - 3372963849069133824t^{10} + 4416069430828597248t^{9} - 4022860158357995520t^{8} + 2370716600434163712t^{7} - 828744519930347520t^{6} + 145881003750064128t^{5} - 7392016673538048t^{4} - 29686813949952t^{3}\]
Info about rational points
Comments on finding rational points None
Elliptic curve whose $2$-adic image is the subgroup $y^2 + xy + y = x^3 - x^2 - 26842505x + 54748901247$, with conductor $3150$
Generic density of odd order reductions $11/112$

Back to the 2-adic image homepage.