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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 89 |
| 5 | 55 |
| 6 | 377 |
| 7 | 1597 |
| 8 | 987 |
| 9 | 121393 |
| 10 | 39088169 |
| 11 | 28657 |
| 12 | 514229 |
| 13 | 3524578 |
| 14 | 24157817 |
| 15 | 1134903170 |
| 16 | 102334155 |
| 17 | 165580141 |
| 18 | 701408733 |
| 19 | 2504730781961 |
| 20 | 956722026041 |
| 21 | 1836311903 |
| 22 | 139583862445 |
| 23 | 6557470319842 |
| 24 | 591286729879 |
| 25 | 17167680177565 |
| 26 | 4052739537881 |
| 27 | 806515533049393 |
[0,1,3,13,89,55,377,1597,987,121393,39088169, 28657,514229,3524578,24157817,1134903170, 102334155,165580141,701408733,2504730781961, 956722026041,1836311903,139583862445, 6557470319842,591286729879,17167680177565, 4052739537881,806515533049393] |