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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 24 |
| 4 | 240 |
| 5 | 3120 |
| 6 | 46410 |
| 7 | 823536 |
| 8 | 16773120 |
| 9 | 387419760 |
| 10 | 9999899910 |
| 11 | 285311670600 |
| 12 | 8916097441680 |
| 13 | 302875106592240 |
| 14 | 11112006720144330 |
| 15 | 437893890380096640 |
| 16 | 18446744069414584320 |
| 17 | 827240261886336764160 |
| 18 | 39346408075098144278664 |
| 19 | 1978419655660313589123960 |
[1,2,24,240,3120,46410,823536,16773120,387419760, 9999899910,285311670600,8916097441680, 302875106592240,11112006720144330, 437893890380096640,18446744069414584320, 827240261886336764160,39346408075098144278664, 1978419655660313589123960] |