Magma V2.21-9 Fri Mar 11 2016 08:13:49 on lehner [Seed = 3295823741] Type ? for help. Type -D to quit. Loading startup file "/home/samir/.magmarc" The modular curve X_0(20) is the elliptic curve Elliptic Curve defined by y^2 = x^3 + x^2 + 4*x + 4 over Rational Field with Cremona label 20a1 Points on X_0(20) over Q(zeta_7)^+ are [ (0 : 1 : 0), (4 : 10 : 1), (0 : 2 : 1), (-1 : 0 : 1), (0 : -2 : 1), (4 : -10 : 1) ] The cusps of X_0(20) are [ Place at (4 : 10 : 1), Place at (4 : -10 : 1), Place at (-1 : 0 : 1), Place at (0 : -2 : 1), Place at (0 : 2 : 1), Place at (0 : 1 : 0) ] Thus every Q(zeta_7)^+ point on X_0(20) is a cusp. The modular curve X_0(11) is the elliptic curve Elliptic Curve defined by y^2 + y = x^3 - x^2 - 10*x - 20 over Rational Field with Cremona label 11a1 Points on X_0(11) over Q(zeta_7)^+ are [ (0 : 1 : 0), (5 : -6 : 1), (16 : 60 : 1), (16 : -61 : 1), (5 : 5 : 1) ] The cusps of X_0(11) are [ Place at (16 : 60 : 1), Place at (0 : 1 : 0) ] The non-cuspidal points on X_0(11) over Q(zeta_7)^+ are [ (5 : -6 : 1), (16 : -61 : 1), (5 : 5 : 1) ] These have j-invariants [ -32768, -121, -24729001 ] Total time: 8.000 seconds, Total memory usage: 56.06MB