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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 3 |
| 7 | 9 |
| 8 | 19 |
| 9 | 52 |
| 10 | 193 |
| 11 | 866 |
| 12 | 4709 |
| 13 | 29160 |
| 14 | 204475 |
| 15 | 1745781 |
| 16 | 17973283 |
| 17 | 218163477 |
| 18 | 3154013451 |
| 19 | 54291505832 |
| 20 | 1101846202608 |
| 21 | 26444293196609 |
| 22 | 754399567634635 |
| 23 | 25615826491870630 |
| 24 | 1034470468747498026 |
[1,1,1,1,1,3,9,19,52,193,866,4709,29160,204475, 1745781,17973283,218163477,3154013451,54291505832, 1101846202608,26444293196609,754399567634635, 25615826491870630,1034470468747498026] |