3

Part of 2021 Taiwan TST Round 1

Problems(1)

Easy pudding equation in Taiwan TST

Source: 2021 Taiwan TST Round 1 Mock Day 1 P3

Find all triples

(x, y, z)

of positive integers such that

x^2 + 4^y = 5^z.

Proposed by Li4 and ltf0501

Diophantine equationnumber theoryTaiwan