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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 39 |
| 2 | 315 |
| 3 | 1687 |
| 4 | 7470 |
| 5 | 29634 |
| 6 | 109421 |
| 7 | 384105 |
| 8 | 1298613 |
| 9 | 4264835 |
| 10 | 13686456 |
| 11 | 43102644 |
| 12 | 133636825 |
| 13 | 408900987 |
| 14 | 1237114335 |
| 15 | 3706490479 |
| 16 | 11010661266 |
| 17 | 32463981270 |
| 18 | 95081107013 |
| 19 | 276820695645 |
| 20 | 801633669561 |
[1,39,315,1687,7470,29634,109421,384105,1298613, 4264835,13686456,43102644,133636825,408900987, 1237114335,3706490479,11010661266,32463981270, 95081107013,276820695645,801633669561] |