(defun count-semi-primes (n p q)
  (let ((primes (make-array (1+ n) :initial-element t))
        (semi-primes (make-array (1+ n) :initial-element 0)))
    (loop for i from 2 while (<= (* i i) n)
          do (when (aref primes i)
               (loop for k from (* i i) to n by i
                     do (setf (aref primes k) nil))))
    (loop for k from 2 while (<= (* k k) n)
          do (when (aref primes k)
               (loop for i from 2 while (<= (* i k) n)
                     do (when (aref primes i)
                          (setf (aref semi-primes (* k i)) 1)))))
    (loop for i from 1 to n
          do (incf (aref semi-primes i) (aref semi-primes (1- i))))
    (loop for v in p
          for qi in q
          collect (- (aref semi-primes qi) (aref semi-primes (1- v))))))