We make several improvements to methods for finding integer solutions to [Formula: see text] for small values of k. We implemented these improvements on Charity Engine's global compute grid of 500,000 volunteer PCs and found new representations for several values of k, including 3 and 42. This completes the search begun by Miller and Woollett in 1954 and resolves a challenge posed by Mordell in 1953.
Keywords: Diophantine equations; Hilbert’s tenth problem; sums of three cubes.
Copyright © 2021 the Author(s). Published by PNAS.