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Twelve Divisor Trial (Posted on 2010-04-09) Difficulty: 3 of 5
Barbara writes a sequence of integers starting with the number 12. Each subsequent integer she writes is chosen randomly with equal probability from amongst the positive divisors of the previous integer (including the possibility of the integer itself). She keeps writing integers until she writes the integer 1 for the first time, and then she stops.

An example of one such sequence is 12, 6, 6, 3, 3, 3, 1.

What is the expected value of the number of terms in Barbara’s sequence?

No Solution Yet Submitted by K Sengupta    
Rating: 3.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Question re: analytical solution ???? | Comment 6 of 7 |
(In reply to analytical solution by Daniel)

I ERRED, OK- but how did you get the right answer?

 from       3e6=11  you get   e6=11/4
.... and still the final answer is right...

  Posted by Ady TZIDON on 2010-04-09 17:31:49
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