Quartic twist y^2 = x^3 + 604907060241651475 x: the curve y^2 = x^3 + 4Bx (2-isogenous to y^2 = x^3 - Bx), reduced mod 4th powers, where B = B(89,102,168,214) is the parametrization of Aguirre, Castaneda and Peral (Aguirre, Castaneda, Peral, 'High rank elliptic curves with torsion group Z/(2Z)', Math. Comp. 73 (2004) 323-331, doi:10.1090/S0025-5718-03-01547-3, https://www.ams.org/mcom/2004-73-245/S0025-5718-03-01547-3/). Found by a Mestre-Nagao sieve over all quadruples a1<a2<a3<a4 with a1^2+a2^2+a3^2+a4^2 < 3*10^5.
David Renshaw ·