1,11,21,1211,111221,??,??

• 1=one 1(11)
  11=two 1's(21)
  21=one 2 one 1(1211)
  1211=one 1 one 2 two 1's(111221)
  111221=three 1's two 2's one 1(312211)
  312211=one 3 one 1 two 2's two 1's(13112221)
• 11 years agoHelpfull: Yes(2) No(0)
• Each number describes the one before it:
  
  1 One
  11 One One
  21 Two One(s)
  1211 One Two and One One(s)
  111221 One One, One Two, and Two One(s)
  
  312211 Three One(s), Two Two(s), and One One
• 11 years agoHelpfull: Yes(0) No(0)