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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 12 |
| 2 | 116 |
| 3 | 1056 |
| 4 | 9424 |
| 5 | 83520 |
| 6 | 738368 |
| 7 | 6521856 |
| 8 | 57587968 |
| 9 | 508443648 |
| 10 | 4488860672 |
| 11 | 39629905920 |
| 12 | 349870772224 |
| 13 | 3088811900928 |
| 14 | 27269361188864 |
| 15 | 240745601040384 |
| 16 | 2125405099196416 |
| 17 | 18763984361226240 |
| 18 | 165656469557215232 |
[1,12,116,1056,9424,83520,738368,6521856,57587968, 508443648,4488860672,39629905920,349870772224, 3088811900928,27269361188864,240745601040384, 2125405099196416,18763984361226240, 165656469557215232] |