Problem 52567. Easy Sequences 7: Easy as Composite Pi
I mean...doing this above 1e10 won't be easy anyway, no matter prime or composite.
Yes, they're really the same problem, as (designating the composite counting function as κ(n)), κ(n) + 𝜋(n) + 1 = n. There are techniques to do the count without creating an array for x>√n, and even for x>∛n.
If anyone does find a way to solve this precisely without some hack, please, publish a scientific paper, and do not post your code here. This problem is not made from an easy sequence at all.
Problem Recent Solvers4
Project Euler: Problem 3, Largest prime factor
Pseudo Square Root (Inspired by Project Euler 266)
Splitting Square - Problem the second
Compute the nth term from the golden sieve
More from this Author104
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!Start Hunting!