577

Part of 1992 All Soviet Union Mathematical Olympiad

Problems(1)

ASU 577 Commonwealth of Independent States 1991 digits ^a+1, k^b+1

Source:

Find all integers

k > 1

such that for some distinct positive integers

a, b

k^a + 1

can be obtained from

k^b + 1

by reversing the order of its (decimal) digits.

number theoryDigits