PUMaC 2010 · 数论（A 组） · 第 3 题
PUMaC 2010 — Number Theory (Division A) — Problem 3
题目详情
- Find the sum of the first 5 positive integers n such that n − 1 is the product of 3 distinct primes.
解析
- Find the sum of the first 5 positive integers n such that n − 1 is the product of 3 distinct primes. Solution: The five numbers are 14, 16, 20, 22, and 32, for an answer of 104.