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
-
Find the peak 3n+1 sequence value
2499 Solvers
-
Number of 1s in a binary string
9100 Solvers
-
Fermat's Last Theorem - Fermat's conjecture
100 Solvers
-
83 Solvers
-
5186 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!