Pollock's conjectures are closely related conjectures in additive number theory. They were first stated in 1850 by Sir Frederick Pollock, better known as a lawyer and politician, but also a contributor of papers on mathematics to the Royal Society. These conjectures are a partial extension of the Fermat polygonal number theorem to three-dimensional figurate numbers, also called polyhedral numbers.

The numbers that are not the sum of at most 4 tetrahedral numbers are given by the sequence 17, 27, 33, 52, 73, ..., (sequence A000797 in the OEIS) of 241 terms, with 343,867 conjectured to be the last such number.

This conjecture has been proven for all sufficiently large numbers. Namely, every number greater than ${\displaystyle e^{10^{7}}\approx 6.59\cdot 10^{4342944}}$ is sufficiently large.

The cube numbers case was established from 1909 to 1912 by Wieferich and A. J. Kempner.

These two conjectures are corrected and confirmed true in 2025.

This conjecture was confirmed as true in 2023.