1 thought on “How many numbers in the form of 2^n -1, which are<br />
less than 5000 are prime?<br />”
Answer: 8179
The largest prime derived from a two-digit prime by inserting the sum of its digits in between. The only prime less than a googol of form 2^n-n, where n is an emirp, (n=13).
Answer: 8179
The largest prime derived from a two-digit prime by inserting the sum of its digits in between. The only prime less than a googol of form 2^n-n, where n is an emirp, (n=13).