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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 78 |
| 3 | 780 |
| 4 | 8790 |
| 5 | 90708 |
| 6 | 1015692 |
| 7 | 10964760 |
| 8 | 122893926 |
| 9 | 1370476932 |
| 10 | 15518261220 |
| 11 | 176063641512 |
| 12 | 2014426860540 |
| 13 | 23109736996680 |
| 14 | 266397931733208 |
| 15 | 3079014279154224 |
| 16 | 35695144493030022 |
| 17 | 414708043501061988 |
| 18 | 4828444403991450612 |
| 19 | 56314242827277224712 |
| 20 | 657855733949279381652 |
[1,6,78,780,8790,90708,1015692,10964760,122893926, 1370476932,15518261220,176063641512,2014426860540, 23109736996680,266397931733208,3079014279154224, 35695144493030022,414708043501061988, 4828444403991450612,56314242827277224712, 657855733949279381652] |