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| n | a(n) |
|---|---|
| -1 | 2 |
| 0 | 6 |
| 1 | 14 |
| 2 | 71 |
| 3 | 190 |
| 4 | 610 |
| 5 | 1929 |
| 6 | 5946 |
| 7 | 17765 |
| 8 | 51094 |
| 9 | 140062 |
| 10 | 409194 |
| 11 | 1196690 |
| 12 | 3481113 |
| 13 | 10126390 |
| 14 | 29457184 |
| 15 | 85689537 |
| 16 | 249266759 |
| 17 | 725105060 |
| 18 | 2109295881 |
| 19 | 6135840666 |
| 20 | 17848866544 |
[2,6,14,71,190,610,1929,5946,17765,51094,140062, 409194,1196690,3481113,10126390,29457184,85689537, 249266759,725105060,2109295881,6135840666, 17848866544] |