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b|2a + 1, c|2b + 1, a|2c + 1 - All-Russian MO 2000 Regional (R4) 9.2

Source:

September 26, 2024
number theorydivisibledivides

Problem Statement

Are there different mutually prime natural numbers aa, bb and cc, greater than 11, such that 2a+12a + 1 is divisible by bb, 2b+12b + 1 is divisible by cc and 2c+12c + 1 is divisible by aa?