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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 30 |
| 4 | 284 |
| 5 | 3130 |
| 6 | 47082 |
| 7 | 823550 |
| 8 | 16782664 |
| 9 | 387422928 |
| 10 | 10000094720 |
| 11 | 285311670622 |
| 12 | 8916102486528 |
| 13 | 302875106592266 |
| 14 | 11112006871683606 |
| 15 | 437893890382576560 |
| 16 | 18446744074918103056 |
| 17 | 827240261886336764194 |
| 18 | 39346408075331452862196 |
[1,6,30,284,3130,47082,823550,16782664,387422928, 10000094720,285311670622,8916102486528, 302875106592266,11112006871683606, 437893890382576560,18446744074918103056, 827240261886336764194,39346408075331452862196] |