DescTools (version 0.99.60)

Primes: Find All Primes Less Than n

Description

Find all prime numbers aka ‘primes’ less than $n$.

Uses an obvious sieve method and some care, working with logical and integers to be quite fast.

Usage

Primes(n)

Value

numeric vector of all prime numbers $\le n$.

Arguments

n

a (typically positive integer) number.

Author

Bill Venables ($\le n$); Martin Maechler gained another 40% speed, working with logicals and integers.

Details

As the function only uses max(n), n can also be a vector of numbers.

See Also

Factorize, GCD, LCM, IsPrime

Examples

(p1 <- Primes(100))
system.time(p1k <- Primes(1000)) # still lightning ..

stopifnot(length(p1k) == 168)