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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 11 |
| 3 | 57 |
| 4 | 245 |
| 5 | 1294 |
| 6 | 6781 |
| 7 | 37728 |
| 8 | 213225 |
| 9 | 1235908 |
| 10 | 7267625 |
| 11 | 43355213 |
| 12 | 261455499 |
| 13 | 1592057090 |
| 14 | 9772992459 |
| 15 | 60420010845 |
| 16 | 375850271829 |
| 17 | 2350842606832 |
| 18 | 14775426937345 |
| 19 | 93270580122351 |
| 20 | 591082988357567 |
| 21 | 3759155772624834 |
[1,6,11,57,245,1294,6781,37728,213225,1235908, 7267625,43355213,261455499,1592057090,9772992459, 60420010845,375850271829,2350842606832, 14775426937345,93270580122351,591082988357567, 3759155772624834] |