Using functional programming to find primes is tricky: https://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf https://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf

Using functional programming to find primes is tricky: https://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf https://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf Melissa O'Neill shows that the typical FP sieve has worse big-O complexity than imperative. https://wiki.haskell.org/Prime_numbers#Sieve_of_Eratosthenes https://wiki.haskell.org/Prime_numbers#Sieve_of_Eratosthenes The Haskell wiki gives several sieve implementations and can't figure out the big-O complexity. (The imperative sieve is O(n log log n).)