section_path: Subclasses of the integers/Even and odd numbers
section_name: Even and odd numbers
paragraph_text: Even and odd numbers
  
  An even number is an integer that is "evenly divisible" by two, that is divisible by two without remainder; an odd number is an integer that is not even. (The old-fashioned term "evenly divisible" is now almost always shortened to " divisible ".) Any odd number n may be constructed by the formula n = 2 k + 1, for a suitable integer k. Starting with k = 0, the first non-negative odd numbers are {1, 3, 5, 7,...}. Any even number m has the form m = 2 k where k is again an integer. Similarly, the first non-negative even numbers are {0, 2, 4, 6,...}.