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

Home > Numbers
Some prime sequences (Posted on 2018-07-04) Difficulty: 3 of 5
What numbers N are the sum of a sequence of consecutive primes such that the product of the first and last numbers in the sequence is N?

No Solution Yet Submitted by Ady TZIDON    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
re: The sequence | Comment 5 of 11 |
(In reply to The sequence by Jer)

By its nature, the solutions to this puzzle must be semiprimes, being the product of the first prime in the sequence and the last number (prime) in the sequence. The fourth number in each of these sequences is not a semiprime:

 2935561623745 = 5*19*53*61* 9557887
 10225245560 = 2*2*2*5*503*508213

I'm still trying to figure out the difference between these two sequences.

Edited on July 5, 2018, 7:48 pm
  Posted by Charlie on 2018-07-05 10:58:19

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 (0)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2020 by Animus Pactum Consulting. All rights reserved. Privacy Information