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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 58 |
| 5 | 501 |
| 6 | 5452 |
| 7 | 74211 |
| 8 | 1257414 |
| 9 | 26480393 |
| 10 | 689598502 |
| 11 | 21957924255 |
| 12 | 844532153323 |
| 13 | 38719749230469 |
| 14 | 2091808065954023 |
| 15 | 131835936103587004 |
| 16 | 9607988537163939224 |
| 17 | 803620426590302536069 |
| 18 | 76622443259122023510169 |
[1,1,2,9,58,501,5452,74211,1257414,26480393, 689598502,21957924255,844532153323,38719749230469, 2091808065954023,131835936103587004, 9607988537163939224,803620426590302536069, 76622443259122023510169] |