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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 59 |
| 5 | 294 |
| 6 | 1549 |
| 7 | 8477 |
| 8 | 47715 |
| 9 | 274468 |
| 10 | 1606284 |
| 11 | 9533595 |
| 12 | 57247969 |
| 13 | 347169053 |
| 14 | 2123148153 |
| 15 | 13079296531 |
| 16 | 81087402683 |
| 17 | 505543820304 |
| 18 | 3167578950478 |
| 19 | 19935616736595 |
| 20 | 125971005957924 |
| 21 | 798883392476824 |
| 22 | 5083047458454395 |
| 23 | 32439034490697090 |
[1,1,3,13,59,294,1549,8477,47715,274468,1606284, 9533595,57247969,347169053,2123148153,13079296531, 81087402683,505543820304,3167578950478, 19935616736595,125971005957924,798883392476824, 5083047458454395,32439034490697090] |