gistfile1.cl

(defun solve-helper (primes candidates)
  (let ((first-number (car candidates)))
    (if first-number
        (solve-helper (cons first-number primes)
                      (remove-if #'(lambda (n)
                                     (declare (integer n))
                                     (= 0 (mod n first-number)))
                                 (cdr candidates)))
        primes)))

(defun euler-solver (n)
  (labels ()
    (let ((candidates (loop
                       for a from 2 to n
                       collect
                         a))
          (primes nil))
      (solve-helper primes candidates))))