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Sum of numbers with largest prime divisor odd

Source: Pan-American Girls’ Mathematical Olympiad 2023 P1

August 8, 2023

smallest prime divisorLargest prime divisornumber theoryPAGMO

Problem Statement

An integer

n \geq 2

is said to be tuanis if, when you add the smallest prime divisor of

n

and the largest prime divisor of

n

(these divisors can be the same), you obtain an odd result. Calculate the sum of all tuanis numbers that are less or equal to

2023