n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 1 |
3 | 1 |
4 | 5 |
5 | 20 |
6 | 109 |
7 | 695 |
8 | 5142 |
9 | 43193 |
10 | 406016 |
11 | 4222569 |
12 | 48137291 |
13 | 596902408 |
14 | 7998492273 |
15 | 115178288736 |
16 | 1773745646540 |
17 | 29089428603255 |
18 | 506156057696641 |
19 | 9313271461618196 |
20 | 180677466355392996 |
21 | 3685820313650017111 |
[1,0,1,1,5,20,109,695,5142,43193,406016,4222569, 48137291,596902408,7998492273,115178288736, 1773745646540,29089428603255,506156057696641, 9313271461618196,180677466355392996, 3685820313650017111] |