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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 23 |
| 6 | 63 |
| 7 | 155 |
| 8 | 448 |
| 9 | 1152 |
| 10 | 3452 |
| 11 | 9158 |
| 12 | 28178 |
| 13 | 76538 |
| 14 | 240368 |
| 15 | 665100 |
| 16 | 2123379 |
| 17 | 5964156 |
| 18 | 19301178 |
| 19 | 54890366 |
| 20 | 179679030 |
| 21 | 516360755 |
| 22 | 1706896545 |
| 23 | 4949350203 |
| 24 | 16500278295 |
| 25 | 48216373545 |
| 26 | 161946759019 |
| 27 | 476447428528 |
| 28 | 1610847688579 |
| 29 | 4767486352733 |
| 30 | 16213635060406 |
[1,1,2,4,10,23,63,155,448,1152,3452,9158,28178, 76538,240368,665100,2123379,5964156,19301178, 54890366,179679030,516360755,1706896545, 4949350203,16500278295,48216373545,161946759019, 476447428528,1610847688579,4767486352733, 16213635060406] |