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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 8 |
| 3 | 74 |
| 4 | 758 |
| 5 | 8412 |
| 6 | 98605 |
| 7 | 1201739 |
| 8 | 15075377 |
| 9 | 193374064 |
| 10 | 2524704727 |
| 11 | 33440460233 |
| 12 | 448246477551 |
| 13 | 6069174992443 |
| 14 | 82884604316537 |
| 15 | 1140361539606239 |
| 16 | 15791577929661603 |
| 17 | 219930850717175458 |
| 18 | 3078540089119391233 |
| 19 | 43287917046150591163 |
| 20 | 611156850554916771425 |
[1,1,8,74,758,8412,98605,1201739,15075377, 193374064,2524704727,33440460233,448246477551, 6069174992443,82884604316537,1140361539606239, 15791577929661603,219930850717175458, 3078540089119391233,43287917046150591163, 611156850554916771425] |