in reply to Re^2: A script with a loop is running my computer Out of memory
in thread A script with a loop is running my computer Out of memory

Dunno if it matters, but

0 + 1 + 2 + .. + ($n-1)

can be calculated using

$n * ($n-1) / 2

So

( 0 + 1 + 2 + .. + ($n-1) ) / $n

is simply

($n-1) / 2