n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 0 |
4 | 21 |
5 | 120 |
6 | 585 |
7 | 2508 |
8 | 10122 |
9 | 39042 |
10 | 145974 |
11 | 532704 |
12 | 1907451 |
13 | 6725004 |
14 | 23407287 |
15 | 80591148 |
16 | 274899288 |
17 | 930128646 |
18 | 3124838844 |
19 | 10432356000 |
20 | 34634029713 |
21 | 114403303008 |
22 | 376184538165 |
23 | 1231890463020 |
24 | 4018920819606 |
[0,0,0,0,21,120,585,2508,10122,39042,145974, 532704,1907451,6725004,23407287,80591148, 274899288,930128646,3124838844,10432356000, 34634029713,114403303008,376184538165, 1231890463020,4018920819606] |