Found in a rational-parameter search of the Kubert–Tate family for torsion ℤ/8ℤ: y^2 + (1-c)xy - by = x^3 - bx^2 with b=(2t-1)(t-1), c=b/t, at t = -4/13; converted to the global minimal model. The 2 witness points were found with PARI/GP ellrank. Conductor 6618066, torsion ℤ/8ℤ.
David Renshaw ·