Arghl..gerade hab ich wieder über eine Stunde damit zugebracht, folgendes Project Euler Problem zu lösen:
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, n < 10^8, have precisely two, not necessarily distinct, prime factors?
Ich kann es einfach nicht lassen..
Dabei ist es schon 2 Uhr!