Specialization at t = -79491/16285 of the generic rank-4 Mordell family associated with the Burkhardt quartic, with parameters (a,b,c,d) = (-43/36,-5/12,1/4,7/9).
Found using a Mestre–Nagao sieve combined with p-adic coefficient reduction. The specialization satisfies m = 103n (mod 637), guaranteeing a sixth-power factor 637^6 in the integral Mordell coefficient. An additional factor 17^6 produces an especially compact model.
PARI/GP 2.17.4 verifies exact rank 10, with bounds [10,10] and 10 independent rational points.
jesper-petersen ·