The modular curve $X_{239b}$

Curve name $X_{239b}$
Index $96$
Level $32$
Genus $0$
Does the subgroup contain $-I$? No
Generating matrices $ \left[ \begin{matrix} 15 & 15 \\ 6 & 3 \end{matrix}\right], \left[ \begin{matrix} 29 & 29 \\ 0 & 1 \end{matrix}\right]$
Images in lower levels
LevelIndex of imageCorresponding curve
$2$ $3$ $X_{6}$
$4$ $6$ $X_{9}$
$8$ $24$ $X_{37d}$
$16$ $48$ $X_{123d}$
Meaning/Special name
Chosen covering $X_{239}$
Curves that $X_{239b}$ minimally covers
Curves that minimally cover $X_{239b}$
Curves that minimally cover $X_{239b}$ and have infinitely many rational points.
Model $\mathbb{P}^{1}$, a universal elliptic curve over an appropriate base is given by \[y^2 = x^3 + A(t)x + B(t), \text{ where}\] \[A(t) = -756t^{32} - 13824t^{31} - 38016t^{30} + 1257984t^{29} + 16039296t^{28} + 66963456t^{27} - 231565824t^{26} - 4636624896t^{25} - 30197041920t^{24} - 121783246848t^{23} - 346143836160t^{22} - 760381267968t^{21} - 1500984317952t^{20} - 3151317270528t^{19} - 6790311419904t^{18} - 12378319257600t^{17} - 16212489320448t^{16} - 12120808882176t^{15} + 1420736495616t^{14} + 16306891259904t^{13} + 21383523237888t^{12} + 14311390445568t^{11} + 3081581494272t^{10} - 3899081097216t^{9} - 5066891919360t^{8} - 3466636296192t^{7} - 1762125152256t^{6} - 734458281984t^{5} - 249580486656t^{4} - 64097353728t^{3} - 11154751488t^{2} - 1132462080t - 49545216\] \[B(t) = -7344t^{48} - 228096t^{47} - 1783296t^{46} + 19229184t^{45} + 462309120t^{44} + 2975616000t^{43} - 6666541056t^{42} - 252556683264t^{41} - 1988117042688t^{40} - 6747626557440t^{39} + 16810441629696t^{38} + 382441504333824t^{37} + 2872083213103104t^{36} + 14665967556968448t^{35} + 56535279022080000t^{34} + 166055265929428992t^{33} + 349914212481871872t^{32} + 392427624079687680t^{31} - 505440014385807360t^{30} - 3915677458134466560t^{29} - 11380046589762600960t^{28} - 22176780819953614848t^{27} - 31246634414150516736t^{26} - 30704055260021784576t^{25} - 16008283247955148800t^{24} + 8421764080550805504t^{23} + 31313010525487497216t^{22} + 43298557511482736640t^{21} + 42452562827412504576t^{20} + 31383758135151820800t^{19} + 12899349951808536576t^{18} - 8623901100661014528t^{17} - 24973850881079377920t^{16} - 28556556538522632192t^{15} - 19607238490120519680t^{14} - 6227443568747741184t^{13} + 3160628383658803200t^{12} + 5923598974517772288t^{11} + 4513493882461224960t^{10} + 2258428448106086400t^{9} + 789879246683111424t^{8} + 183318721572372480t^{7} + 20007071671910400t^{6} - 3386427630944256t^{5} - 2020058679214080t^{4} - 447070662033408t^{3} - 56532507033600t^{2} - 4000762036224t - 123211874304\]
Info about rational points
Comments on finding rational points None
Elliptic curve whose $2$-adic image is the subgroup $y^2 = x^3 - x^2 - 9x - 7$, with conductor $128$
Generic density of odd order reductions $410657/1835008$

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