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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 9 |
| 5 | 11 |
| 6 | 295 |
| 7 | 337 |
| 8 | 13041 |
| 9 | 45550 |
| 10 | 1043211 |
| 11 | 3359786 |
| 12 | 150500053 |
| 13 | 440947300 |
| 14 | 23238057921 |
| 15 | 145733451241 |
| 16 | 5097210717873 |
| 17 | 29028404123105 |
| 18 | 1710073810205317 |
| 19 | 8663532297784519 |
| 20 | 574604164708374861 |
| 21 | 5108822296820280256 |
| 22 | 246335435270285805885 |
[1,0,1,1,9,11,295,337,13041,45550,1043211,3359786, 150500053,440947300,23238057921,145733451241, 5097210717873,29028404123105,1710073810205317, 8663532297784519,574604164708374861, 5108822296820280256,246335435270285805885] |