euler72_alt_slow.sh


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

#!/bin/bash

euler_phi() {
	prime_factors=($(factor $1 | cut -d ' ' -f2- | tr ' ' '\n' | sort -u))
	t=$1
	for i in ${prime_factors[@]}
	do
		t=$(($t/$i*($i-1)))
	done
	echo $t
}

sum=0
i=2
while [[ $i -le 1000000 ]]
do
	sum=$(($sum+$(euler_phi $i)))
	i=$(($i+1))
done
echo $sum