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

Home > Numbers
Semiprimes and Emirps (Posted on 2023-01-14) Difficulty: 3 of 5
Determine the total number of semiprimes below 2023, that are immediately followed by an emirp.

For example, 22 is a semiprime which is immediately followed by 23. But 23 is NOT an emirp, since 32 is composite.

List all valid pairs in conformity with the provisions of the problem.

*** Computer program/ excel solver aided methods are welcome, but a semi-analytic methodology is preferred.

See The Solution Submitted by K Sengupta    
Rating: 5.0000 (1 votes)

Comments: ( You must be logged in to post comments.)
  Subject Author Date
re(2): semi-analytic solutionSteven Lord2023-01-14 11:16:03
re: semi-analytic solutionCharlie2023-01-14 11:05:15
Solutioncomputer solutionCharlie2023-01-14 11:01:12
semi-analytic solutionSteven Lord2023-01-14 10:54:39
SolutionComputer solutionLarry2023-01-14 10:09:25
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (15)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information