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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 16 |
| 4 | 36 |
| 5 | 84 |
| 6 | 273 |
| 7 | 648 |
| 8 | 2114 |
| 9 | 4757 |
| 10 | 16516 |
| 11 | 37161 |
| 12 | 87045 |
| 13 | 282896 |
| 14 | 673924 |
| 15 | 2184233 |
| 16 | 5263877 |
| 17 | 17107472 |
| 18 | 38830244 |
| 19 | 134554132 |
| 20 | 303080705 |
| 21 | 707272770 |
| 22 | 2300725397 |
| 23 | 5457925252 |
| 24 | 17805431433 |
| 25 | 42970665029 |
| 26 | 139654661284 |
| 27 | 314223120404 |
| 28 | 1099646108737 |
| 29 | 2474203744786 |
[1,2,5,16,36,84,273,648,2114,4757,16516,37161, 87045,282896,673924,2184233,5263877,17107472, 38830244,134554132,303080705,707272770,2300725397, 5457925252,17805431433,42970665029,139654661284, 314223120404,1099646108737,2474203744786] |