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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 54 |
| 5 | 323 |
| 6 | 2241 |
| 7 | 17671 |
| 8 | 155755 |
| 9 | 1512825 |
| 10 | 16017287 |
| 11 | 183318386 |
| 12 | 2252439489 |
| 13 | 29539906896 |
| 14 | 411465894871 |
| 15 | 6061717452230 |
| 16 | 94103831065202 |
| 17 | 1534537091424337 |
| 18 | 26210557169790053 |
| 19 | 467745495221383190 |
| 20 | 8701568001160424952 |
| 21 | 168405853681337658542 |
| 22 | 3384457796699512302326 |
[1,1,3,11,54,323,2241,17671,155755,1512825, 16017287,183318386,2252439489,29539906896, 411465894871,6061717452230,94103831065202, 1534537091424337,26210557169790053, 467745495221383190,8701568001160424952, 168405853681337658542,3384457796699512302326] |