All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Numbers
Though this be madness, yet there is method in it... (Posted on 2012-09-20) Difficulty: 2 of 5
From a posting to the Math Fun mailing list by R. W. Gosper, Dec 03 2009:

Gosper: I just reordered checks.
Bank Lady: Where would you like the numbering to start?
Gosper: What was my last one?
Bank Lady: 1093
Gosper: Well then obviously 3511 .
Bank Lady: [Opens mouth. Decides not to ask. Resumes typing.]

My question : How many checks can you order for Mr. Gosper's checkbook, using his numbering system?

See The Solution Submitted by Ady TZIDON    
Rating: 4.3333 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution Solution | Comment 2 of 6 |
The numbers 1093 and 3511 are known as Wieferich Primes, such that p^2 divides 2^(p-1)-1 and p is a prime.  They are indeed the only two such numbers that are known.  Therefore these are the only 2 checks that can be ordered using this numbering system.
  Posted by Chris, PhD on 2012-09-20 11:56:14
Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (5)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2019 by Animus Pactum Consulting. All rights reserved. Privacy Information