Project Euler Problem 36

euler36.erl

-module(euler36).
-export([is_palindrome/1, solve/0]).

is_palindrome(X) ->
    integer_to_list(X) =:= lists:reverse(integer_to_list(X)).

solve() ->
    % need to check only odd integers since the even ones will never be palindromes in binary base
    solve(lists:seq(1, 999999, 2), 0).

solve([], Sum) ->
    Sum;
solve([H | Tail], Sum) ->
    % the last expression below is converting the number to binary base
    % andalso operator really speeds it up
    Check = is_palindrome(H) andalso is_palindrome(list_to_integer(hd(io_lib:format("~.2B", [H])))),
    case Check of
	true -> solve(Tail, Sum + H);
	false -> solve(Tail, Sum)
    end.

Can you reduce memory consumption? In Haskell, [1..999999] does not allocate megabytes of memory because the language has lazy evaluation. In your example, however, I am guessing that lists:seq(1, 999999, 2) has to create the whole list immediately! You can thread a number instead.