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Can you find the next number in this sequence? - Alex Gendler

  • 481,266 Views
  • 3,835 Questions Answered
  • TEDEd Animation

Let’s Begin…

1, 11, 21, 1211, 111221. These are the first five elements of a number sequence. Can you figure out what comes next? Alex Gendler reveals the answer and explains how beyond just being a neat puzzle, this type of sequence has practical applications as well.

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TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Alex Gendler
  • Director Outis
  • Associate Producer Jessica Ruby
  • Content Producer Gerta Xhelo
  • Editorial Producer Alex Rosenthal
  • Narrator Addison Anderson
  • See more
Additional Resources for you to Explore
Read Conway’s original paper here, or take a closer look at Conway’s Constant and the visual graph of its roots. Or delve deeper into examining the elements and proofs regarding the limits of the sequence.


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About TED-Ed Animations

TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Alex Gendler
  • Director Outis
  • Associate Producer Jessica Ruby
  • Content Producer Gerta Xhelo
  • Editorial Producer Alex Rosenthal
  • Narrator Addison Anderson
  • See more