Project Euler 23

gistfile1.rb

require 'prime'
m = 28123
sum = 0
adn = Array.new()
flag = Array.new(m+1){false}
2.upto(m) do |i|
  a = 1
  i.prime_division.each do |j|
    b = 0
    (j[1]+1).times do |k|
      b += j[0]**k
    end
    a *= b
  end
  a -= i
  adn.push(i) if a > i
end
adn.each do |i|
  adn.each do |j|
    flag[i+j] = true if i + j <= m
  end
end
m.times do |i|
  sum += i if !flag[i]
end
puts sum # 4179871