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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 43 |
| 4 | 181 |
| 5 | 787 |
| 6 | 3491 |
| 7 | 15766 |
| 8 | 72213 |
| 9 | 333972 |
| 10 | 1556483 |
| 11 | 7305176 |
| 12 | 34479175 |
| 13 | 163466387 |
| 14 | 778101574 |
| 15 | 3716946760 |
| 16 | 17808521929 |
| 17 | 85545387623 |
| 18 | 411903327431 |
| 19 | 1987499971566 |
| 20 | 9607721942704 |
| 21 | 46522582503969 |
| 22 | 225619346235805 |
| 23 | 1095696997537555 |
| 24 | 5327841891158836 |
| 25 | 25936928909187264 |
| 26 | 126401369551320654 |
[1,3,11,43,181,787,3491,15766,72213,333972, 1556483,7305176,34479175,163466387,778101574, 3716946760,17808521929,85545387623,411903327431, 1987499971566,9607721942704,46522582503969, 225619346235805,1095696997537555,5327841891158836, 25936928909187264,126401369551320654] |