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
-
6691 Solvers
-
139 Solvers
-
Construct a string from letters and counts
144 Solvers
-
Area of an equilateral triangle
6614 Solvers
-
compress sequence into intervals
95 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!