data/problems/187.yml
---
:id: 187
:name: Semiprimes
:url: https://projecteuler.net/problem=187
:content: |+
A composite is a number containing at least two prime factors. For example, 15 = 3 × 5; 9 = 3 × 3; 12 = 2 × 2 × 3.
There are ten composites below thirty containing precisely two, not necessarily distinct, prime factors: 4, 6, 9, 10, 14, 15, 21, 22, 25, 26.
How many composite integers, <var>n</var> \< 10<sup>8</sup>, have precisely two, not necessarily distinct, prime factors?