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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 17 |
| 3 | 69 |
| 4 | 373 |
| 5 | 1553 |
| 6 | 6817 |
| 7 | 28989 |
| 8 | 122993 |
| 9 | 501825 |
| 10 | 2030857 |
| 11 | 8159201 |
| 12 | 32719377 |
| 13 | 131022473 |
| 14 | 524458461 |
| 15 | 2098531085 |
[1,5,17,69,373,1553,6817,28989,122993,501825, 2030857,8159201,32719377,131022473,524458461, 2098531085] |