Catalan數字
Catalan數字
0
1
1
1
2
2
3
5
4
14
5
42
6
132
7
429
8
1430
9
4862
10
16796
11
58786
12
208012
13
742900
14
2674440
15
9694845
參考資料: Martin Gardner, Time Travel and Other Mathematical Bewilderments, pp. 254-255.