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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 11 |
| 4 | 104 |
| 5 | 1241 |
| 6 | 18216 |
| 7 | 317715 |
| 8 | 6414848 |
| 9 | 147107953 |
| 10 | 3776164000 |
| 11 | 107253230171 |
| 12 | 3339157316736 |
| 13 | 113070818225353 |
| 14 | 4137170839854976 |
| 15 | 162653198951193059 |
| 16 | 6837934005096620032 |
| 17 | 306093463368534049761 |
| 18 | 14535589272368159900160 |
| 19 | 729835620496621069643179 |
[0,1,2,11,104,1241,18216,317715,6414848,147107953, 3776164000,107253230171,3339157316736, 113070818225353,4137170839854976, 162653198951193059,6837934005096620032, 306093463368534049761,14535589272368159900160, 729835620496621069643179] |