n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 3 |
3 | 20 |
4 | 93 |
5 | 499 |
6 | 2520 |
7 | 13049 |
8 | 66867 |
9 | 344140 |
10 | 1767957 |
11 | 9089411 |
12 | 46715760 |
13 | 240130801 |
14 | 1234265763 |
15 | 6344236100 |
16 | 32609631693 |
17 | 167615492179 |
18 | 861552425160 |
19 | 4428427689449 |
20 | 22762359745107 |
21 | 116999783819260 |
22 | 601385308653957 |
23 | 3091153547973731 |
[0,1,3,20,93,499,2520,13049,66867,344140,1767957, 9089411,46715760,240130801,1234265763,6344236100, 32609631693,167615492179,861552425160, 4428427689449,22762359745107,116999783819260, 601385308653957,3091153547973731] |