4

Part of 2022 Grand Duchy of Lithuania

Problems(1)

2^a + 2^b + 2^c + 3 is perfect square

Source: 2022 Grand Duchy of Lithuania, MC p4 (Baltic Way TST) https://artofproblemsolving.com/community/c1321893_grand

Find all triples of natural numbers

(a, b, c)

for which the number

2^a + 2^b + 2^c + 3

is the square of an integer.

number theoryPerfect SquaresPerfect Square