1047

1047

num = int(input())
num_list = [1, 1, 2]
for i in range(2, num):
    method = 0
    if i % 2 == 0:
        method += num_list[i // 2] ** 2
    for j in range((i + 1) // 2):
        method += num_list[j] * num_list[i - j] * 2
    num_list.append(method)
if num == 1:
    print(1)
else:
    print(num_list[len(num_list) - 1])

太久了，只记得好像是有点类似于汉诺塔。