#!/usr/bin/perl

###########################################################################
#
# partialsums.pl
#
# Write a program in the language of your choice to compute and display the first 800,000 partial sums for the infinite series
#
# 1/1^2 + 1/2^2 + 1/3^2 + 1/4^2 + 1/5^2 + 1/6^2 + 1/7^2 + 1/8^2 + 1/9^2 + ...
#
# (c)Ken Owen 2011
#
###########################################################################

use constant PI    => 4 * atan2(1, 1);
my $loops=800000;
my $answer=0;
my $match=PI**(2)/6;

for($i=1; $i<$loops; $i++){
	$answer+=1/$i**2;
	#uncomment the next line to see the progression
	#print "i=" . $i . " answer=" . $answer . "\n"; 
}
print "After " . $loops . " loops, the answer is " . $answer . "\n";
print "PI=" . PI . "\n";
print "pi^2/6=" . $match . "\n";