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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | 10 |
| 5 | 14 |
| 6 | 42 |
| 7 | 90 |
| 8 | 354 |
| 9 | 758 |
| 10 | 2290 |
| 11 | 6002 |
| 12 | 18410 |
| 13 | 51310 |
| 14 | 154106 |
| 15 | 449322 |
| 16 | 1384962 |
| 17 | 4089174 |
| 18 | 12475362 |
| 19 | 37746786 |
| 20 | 116037642 |
| 21 | 355367310 |
| 22 | 1097869386 |
| 23 | 3393063162 |
| 24 | 10546081122 |
| 25 | 32810171382 |
| 26 | 102465452754 |
| 27 | 320522209490 |
| 28 | 1005428474218 |
[1,2,2,10,14,42,90,354,758,2290,6002,18410,51310, 154106,449322,1384962,4089174,12475362,37746786, 116037642,355367310,1097869386,3393063162, 10546081122,32810171382,102465452754,320522209490, 1005428474218] |