Thursday, May 6, 2010

1, 101, 10101, 1010101, ...

Show that, in the sequence 1, 101, 10101, 1010101, ... only the number 101 is prime.
Posted by at
Labels:

1 comment:

  1. AnonymousDecember 16, 2010 at 10:36 PM

    no proof, but here's some prime numbers in a spiral. http://www.flickr.com/photos/modern_carpentry/3896432339/in/set-72157622057420172/

    ReplyDelete

Subscribe to: Post Comments (Atom)