Problem 6 (written in Ruby)
sigma = (1..100).to_a.inject(0){|r,n|r+=n}
puts sigma ** 2 - (1..100).to_a.map{|n|n*n}.inject(0){|r,n|r+=n}
Problem:
http://odz.sakura.ne.jp/projecteuler/index.php?Problem%206
sigma = (1..100).to_a.inject(0){|r,n|r+=n}
puts sigma ** 2 - (1..100).to_a.map{|n|n*n}.inject(0){|r,n|r+=n}
Problem:
http://odz.sakura.ne.jp/projecteuler/index.php?Problem%206