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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 65 |
| 3 | 795 |
| 4 | 6971 |
| 5 | 69317 |
| 6 | 690756 |
| 7 | 6316950 |
| 8 | 55729130 |
| 9 | 484275457 |
| 10 | 4111328940 |
| 11 | 34029153900 |
| 12 | 275901508917 |
| 13 | 2197552381491 |
| 14 | 17207716281240 |
| 15 | 132575879110175 |
| 16 | 1006214596929014 |
| 17 | 7531171360277228 |
| 18 | 55632520744009711 |
| 19 | 405876769498808480 |
| 20 | 2926507055330036936 |
[1,1,65,795,6971,69317,690756,6316950,55729130, 484275457,4111328940,34029153900,275901508917, 2197552381491,17207716281240,132575879110175, 1006214596929014,7531171360277228, 55632520744009711,405876769498808480, 2926507055330036936] |