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(2): a twist, perhaps?

| Comment 8 of 12 |

(In reply to re: a twist, perhaps? by DJ)

"neither of the left-hand members is equal to 101" - I meant neither of the right-hand members (1 + 10^2 + 10^4 + ... + 10^2i) or (10^(2i+1) +1) is equal to 101 when i>1.

Posted by DJ on 2003-05-25 08:16:39

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