Specialization t = 247/229 of a generic rank-4 Mordell family obtained from the Burkhardt quartic, with affine parameters (a,b,c,d) = (4/5,-24/5,6,-9) and generating parameters (u,v,w) = (-1,-4,5).
Found using a sixth-power-residue Mestre–Nagao sieve across Burkhardt surface parameters, with 3-isogeny deduplication and conductor-aware candidate selection.
PARI/GP 2.17.4 establishes exact rank 10, with bounds [10,10] and 10 independent rational points.
jesper-petersen ·