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## 'Fibonacci Factors' printed from http://nrich.maths.org/

In the Fibonacci sequence each term is the sum of the two terms
before it:

1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144...

Where do the even numbers come in the sequence?

Is there a pattern? Why?

Which Fibonacci numbers are divisible by 3?

Prove general results for the occurrence of even Fibonacci numbers
in the sequence and for the occurrence of multiples of 3.