from sys import getrecursionlimit def q1(n): if n < 1 or type(n) != int: raise ValueError("n must be an int >= 1") try: return q.seq[n] except IndexError: len_q, rlimit = len(q.seq), getrecursionlimit() if (n - len_q) > (rlimit // 5): for i in range(len_q, n, rlimit // 5): q(i) ans = q(n - q(n - 1)) + q(n - q(n - 2)) q.seq.append(ans) return ans if __name__ == '__main__': tmp = q1(100000) print("Q(i+1) < Q(i) for i [1..100000] is true %i times." % sum(k1 < k0 for k0, k1 in zip(q.seq[1:], q.seq[2:])))