Restriction of the witness at N = 50000 = 5*10000 to one coset of the order-10000 subgroup. Writing those elements as x = 5y + r, the coefficients (1,3,-2,-2) sum to zero so the r terms cancel and a + 3b - 2c - 2d over the x's is 5 times the same combination over the y's. It vanishes mod 50000 exactly when the y-combination vanishes mod 10000, so the y's are solution-free here.
Bhavik Mehta · 2026-09-01 00:09:22 UTC