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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 14 |
| 4 | 39 |
| 5 | 110 |
| 6 | 312 |
| 7 | 890 |
| 8 | 2550 |
| 9 | 7334 |
| 10 | 21161 |
| 11 | 61226 |
| 12 | 177575 |
| 13 | 516114 |
| 14 | 1502867 |
| 15 | 4383462 |
| 16 | 12804429 |
| 17 | 37452870 |
| 18 | 109682319 |
| 19 | 321563658 |
| 20 | 943701141 |
| 21 | 2772060618 |
| 22 | 8149661730 |
| 23 | 23978203662 |
| 24 | 70600640796 |
| 25 | 208014215066 |
| 26 | 613266903927 |
[1,2,5,14,39,110,312,890,2550,7334,21161,61226, 177575,516114,1502867,4383462,12804429,37452870, 109682319,321563658,943701141,2772060618, 8149661730,23978203662,70600640796,208014215066, 613266903927] |