Problem 56308. Korselt's Criterion
A composite integer n (n>=2) divides b^n-b, i.e. mod(b^n-b,n)==0, for all integers b if and only if n is square-free (doesn't have repeating prime factors) and n-1 is divisible by p-1, i.e. mod(n-1,p-1)==0, for all prime divisors p of n.
Given a positive integer x, return c, the number of integers n satisfying Korselt's Criterion, where 1 < n < 10^x.
Example:
x = 2;
c = 0
Example:
x = 3;
c = 1
Solution Stats
Problem Comments
Solution Comments
Show commentsProblem Recent Solvers6
Suggested Problems
-
2159 Solvers
-
1228 Solvers
-
How to find the position of an element in a vector without using the find function
2690 Solvers
-
Back to basics 12 - Input Arguments
586 Solvers
-
Self-similarity 3 - Every other pair of terms
46 Solvers
More from this Author45
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!