Primes from 1 to N

t1.erl

-module(t1).
-export([primes/1]).

primes(N) -> primeA(1, N, []).
primeA(X, N, L) ->
  if
    X =:= 1 -> primeA(2, N, [1|L]);
    X > N   -> lists:reverse(L);
    true ->
      NL = case length([I || I <- L, X rem I =:= 0]) of
        1 -> [X | L];
        _ -> L
      end,
      primeA(X + 1, N, NL)
  end.