s, t = 2, 11 c = [] n = [] arr = [1] * (s + 1) for k in range(len(c) + 1): s__ = s + 1 if k == 0 else c[k - 1] + 1 s_ = s__ - 1 t__ = c[k] + 1 if k < len(c) else t + 1 t_ = t__ - 1 for i in range(s__, t__): e = 0 if i - 1 >= s_ and not i - 1 in n: e += arr[i - 1] if i % 2 == 1 and (i + 1) // 2 >= s_ and not (i + 1) // 2 in n: e += arr[(i+1) // 2] arr.append(e) back = arr[t_] arr = [0] * (t_ + 1) arr[t_] = back print(arr[t]) # 14