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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
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