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

Home > Just Math
Primed to Square (Posted on 2013-02-15) Difficulty: 3 of 5
What is the largest prime p that makes sqrt(17p+625) an integer?

No Solution Yet Submitted by Danish Ahmed Khan    
Rating: 4.0000 (2 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution computer exploration (probable spoiler) | Comment 1 of 3

 5   P=1
10   while P<9999999999 and P>0
20     P=nxtprm(P)
30     N=17*P+625
40     Sr=int(sqrt(N)+0.5)
50     if Sr*Sr=N then print P;
60   wend

finds only 3 and 67 by the time the program was stopped at p = 82,150,333.

  Posted by Charlie on 2013-02-15 18:24:00
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 (1)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2018 by Animus Pactum Consulting. All rights reserved. Privacy Information