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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 9 |
| 2 | 108 |
| 3 | 1610 |
| 4 | 28560 |
| 5 | 586320 |
| 6 | 13658904 |
| 7 | 355787568 |
| 8 | 10243342296 |
| 9 | 322939137312 |
| 10 | 11063339361360 |
| 11 | 409194048521778 |
| 12 | 16249995494795920 |
| 13 | 689585033717023224 |
| 14 | 31140529927119263136 |
| 15 | 1490994828293677370148 |
| 16 | 75444108490820383882392 |
[1,9,108,1610,28560,586320,13658904,355787568, 10243342296,322939137312,11063339361360, 409194048521778,16249995494795920, 689585033717023224,31140529927119263136, 1490994828293677370148,75444108490820383882392] |