Fiber t = -19733/38399 of a rank-17 elliptic fibration of Elkies' K3 surface (arXiv:2608.25406): the 2-neighbour fibration that also carries wgxli's #356, #385 and #351. Found by a Mestre-Nagao sieve over t = a/b, re-scored at 2^20, followed by an iterated 'bootstrap' 2-covering point search (fake 2-descent over cosets of the growing known lattice, minimal reduced quartic models, ratpoints). Basis LLL-reduced with respect to the canonical height. The 28 points are certified independent by the F2-rank of their images under the 2-descent map at the good primes.
Mundoamundo · 2026-09-04 18:49:50 UTC