perplexus.info :: Numbers : 10001, 100010001, ....

10001, 100010001, .... (Posted on 2003-05-23)

Consider the following sequence:

10001, 100010001, 1000100010001, 10001000100010001, 100010001000100010001,....

Show that none of them are prime numbers.

See The Solution Submitted by Fernando

Rating: 3.3333 (6 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

re: First observations

Comment 12 of 12 |

(In reply to First observations by Brian Smith)

If the number of ones in a member of the sequence is A MULTIPLE OF 3, then the member itself is DIVISIBLE BY 3.

Posted by Ady TZIDON on 2013-02-27 06:54:12

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