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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 9 |
| 3 | 75 |
| 4 | 475 |
| 5 | 2695 |
| 6 | 14443 |
| 7 | 74831 |
| 8 | 379459 |
| 9 | 1896807 |
| 10 | 9388731 |
| 11 | 46152447 |
| 12 | 225762931 |
| 13 | 1100476759 |
| 14 | 5350600939 |
| 15 | 25966867823 |
| 16 | 125848830499 |
| 17 | 609324773703 |
| 18 | 2948038268955 |
| 19 | 14255607687903 |
| 20 | 68907738083539 |
| 21 | 332985156888631 |
[0,9,75,475,2695,14443,74831,379459,1896807, 9388731,46152447,225762931,1100476759,5350600939, 25966867823,125848830499,609324773703, 2948038268955,14255607687903,68907738083539, 332985156888631] |