n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 15 |
4 | 88 |
5 | 505 |
6 | 4056 |
7 | 31549 |
8 | 311816 |
9 | 3083049 |
10 | 36343720 |
11 | 431215741 |
12 | 5937234348 |
13 | 82236865165 |
14 | 1291252453050 |
15 | 20477737537755 |
16 | 361495828272496 |
17 | 6449450737736065 |
18 | 126566562342343176 |
19 | 2509520619696338269 |
20 | 54179963857121953460 |
21 | 1182248224137860933781 |
[1,1,4,15,88,505,4056,31549,311816,3083049, 36343720,431215741,5937234348,82236865165, 1291252453050,20477737537755,361495828272496, 6449450737736065,126566562342343176, 2509520619696338269,54179963857121953460, 1182248224137860933781] |