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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 4 |
| 7 | 9 |
| 8 | 20 |
| 9 | 47 |
| 10 | 112 |
| 11 | 274 |
| 12 | 678 |
| 13 | 1702 |
| 14 | 4314 |
| 15 | 11039 |
| 16 | 28460 |
| 17 | 73875 |
| 18 | 192884 |
| 19 | 506251 |
| 20 | 1334899 |
| 21 | 3534591 |
| 22 | 9394196 |
| 23 | 25052866 |
| 24 | 67019457 |
| 25 | 179793858 |
| 26 | 483591479 |
| 27 | 1303836901 |
| 28 | 3523141231 |
| 29 | 9539570474 |
| 30 | 25879559378 |
| 31 | 70332798052 |
| 32 | 191461351903 |
| 33 | 522012186777 |
| 34 | 1425327940690 |
[1,1,1,2,4,9,20,47,112,274,678,1702,4314,11039, 28460,73875,192884,506251,1334899,3534591,9394196, 25052866,67019457,179793858,483591479,1303836901, 3523141231,9539570474,25879559378,70332798052, 191461351903,522012186777,1425327940690] |