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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 11 |
| 3 | 68 |
| 4 | 351 |
| 5 | 770 |
| 6 | 38851 |
| 7 | 78472 |
| 8 | 431211 |
| 9 | 2665738 |
| 10 | 13759901 |
| 11 | 30185540 |
| 12 | 1523036901 |
| 13 | 3076259342 |
| 14 | 16904333611 |
| 15 | 104502261008 |
| 16 | 539415638651 |
| 17 | 1183333538310 |
| 18 | 59706092554151 |
| 19 | 120595518646612 |
| 20 | 662683685787211 |
| 21 | 4096697633369878 |
| 22 | 21146171852636601 |
[1,2,11,68,351,770,38851,78472,431211,2665738, 13759901,30185540,1523036901,3076259342, 16904333611,104502261008,539415638651, 1183333538310,59706092554151,120595518646612, 662683685787211,4096697633369878, 21146171852636601] |