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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 21 |
| 4 | 172 |
| 5 | 1557 |
| 6 | 14937 |
| 7 | 148870 |
| 8 | 1523150 |
| 9 | 15874211 |
| 10 | 167584946 |
| 11 | 1784250269 |
| 12 | 19082848084 |
| 13 | 204183773733 |
| 14 | 2174724531143 |
| 15 | 22887441573480 |
| 16 | 235016048710027 |
| 17 | 2294441979279215 |
| 18 | 19936497820248076 |
| 19 | 118333942636382173 |
| 20 | -709004900481995789 |
| 21 | -49850788347995316262 |
[1,1,3,21,172,1557,14937,148870,1523150,15874211, 167584946,1784250269,19082848084,204183773733, 2174724531143,22887441573480,235016048710027, 2294441979279215,19936497820248076, 118333942636382173,-709004900481995789, -49850788347995316262] |