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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 10 |
| 3 | 165 |
| 4 | 3620 |
| 5 | 96600 |
| 6 | 2996586 |
| 7 | 105222740 |
| 8 | 4110953640 |
| 9 | 176563668420 |
| 10 | 8262487393200 |
| 11 | 418357209052255 |
| 12 | 22790291724038580 |
| 13 | 1329373540730613885 |
| 14 | 82689132241752729840 |
| 15 | 5464831115387029530825 |
| 16 | 382492359049214499350160 |
| 17 | 28269306654212844076331775 |
| 18 | 2200386909130514596330158960 |
| 19 | 179936864840741390285785502825 |
| 20 | 15424543660650808111807757322400 |
[1,1,10,165,3620,96600,2996586,105222740, 4110953640,176563668420,8262487393200, 418357209052255,22790291724038580, 1329373540730613885,82689132241752729840, 5464831115387029530825,382492359049214499350160, 28269306654212844076331775, 2200386909130514596330158960, 179936864840741390285785502825, 15424543660650808111807757322400] |