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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 9 |
| 4 | 160 |
| 5 | 2525 |
| 6 | 42336 |
| 7 | 788263 |
| 8 | 16454656 |
| 9 | 384154569 |
| 10 | 9963712000 |
| 11 | 284872585811 |
| 12 | 8910352429056 |
| 13 | 302794155321853 |
| 14 | 11110786329481216 |
| 15 | 437874275265339375 |
| 16 | 18446409309071343616 |
| 17 | 827234215200059132177 |
| 18 | 39346292832569834471424 |
| 19 | 1978417344403405821315979 |
[1,0,0,9,160,2525,42336,788263,16454656,384154569, 9963712000,284872585811,8910352429056, 302794155321853,11110786329481216, 437874275265339375,18446409309071343616, 827234215200059132177,39346292832569834471424, 1978417344403405821315979] |