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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 30 |
| 5 | 114 |
| 6 | 436 |
| 7 | 1676 |
| 8 | 6468 |
| 9 | 25040 |
| 10 | 97190 |
| 11 | 378050 |
| 12 | 1473254 |
| 13 | 5750390 |
| 14 | 22476090 |
| 15 | 87958306 |
| 16 | 344593314 |
| 17 | 1351330642 |
| 18 | 5303953012 |
| 19 | 20834616860 |
| 20 | 81900891372 |
| 21 | 322168053848 |
| 22 | 1268071841744 |
| 23 | 4994044075204 |
| 24 | 19678407053280 |
| 25 | 77578340524444 |
| 26 | 305977596195556 |
| 27 | 1207325722552016 |
| 28 | 4765772559893268 |
[1,2,8,30,114,436,1676,6468,25040,97190,378050, 1473254,5750390,22476090,87958306,344593314, 1351330642,5303953012,20834616860,81900891372, 322168053848,1268071841744,4994044075204, 19678407053280,77578340524444,305977596195556, 1207325722552016,4765772559893268] |