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
-
Make the vector [1 2 3 4 5 6 7 8 9 10]
52481 Solvers
-
Replace all zeros and NaNs in a matrix with the string 'error'
103 Solvers
-
I've got the power! (Inspired by Project Euler problem 29)
141 Solvers
-
511 Solvers
-
Pandigital Factors (Based on Euler 491)
41 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!