| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 22 |
| 3 | 1240 |
| 4 | 316316 |
| 5 | 343855008 |
| 6 | 1551088459936 |
| 7 | 28684932916796288 |
| 8 | 2161788213413182113760 |
| 9 | 661624062463590275090838016 |
| 10 | 820418024446932078541699530057216 |
[1,2,22,1240,316316,343855008,1551088459936, 28684932916796288,2161788213413182113760, 661624062463590275090838016, 820418024446932078541699530057216] |