| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 8 |
| 3 | 55 |
| 4 | 377 |
| 5 | 610 |
| 6 | 10946 |
| 7 | 17711 |
| 8 | 121393 |
| 9 | 3524578 |
| 10 | 5702887 |
| 11 | 9227465 |
| 12 | 39088169 |
| 13 | 63245986 |
| 14 | 1836311903 |
| 15 | 20365011074 |
| 16 | 139583862445 |
| 17 | 365435296162 |
| 18 | 591286729879 |
| 19 | 4052739537881 |
| 20 | 17167680177565 |
| 21 | 117669030460994 |
[1,8,55,377,610,10946,17711,121393,3524578, 5702887,9227465,39088169,63245986,1836311903, 20365011074,139583862445,365435296162, 591286729879,4052739537881,17167680177565, 117669030460994] |