Fasten the solution to 10 in bash by halving the tested integers

e0010/euler0010.bash

@@ -1,10 +1,12 @@
-#!/usr/bin/bash
+#!/bin/bash
 
 # I have yet to see this script coming to an end...
 
-declare -i primeSum=0
+declare -i primeSum=2
+sequence=$(seq 3 2 2000000)
 
-for num in {2..2000000}; do 
+for num in $sequence; do
+    echo $num   
     [[ "$(factor $num | cut -d " " -f2)" != $num ]] || primeSum=$(( $primeSum + $num ))
 done
 echo "$primeSum"