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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 26 |
| 4 | 103 |
| 5 | 422 |
| 6 | 1768 |
| 7 | 7520 |
| 8 | 32335 |
| 9 | 140174 |
| 10 | 611530 |
| 11 | 2681516 |
| 12 | 11807683 |
| 13 | 52177166 |
| 14 | 231262945 |
| 15 | 1027703054 |
| 16 | 4577477065 |
| 17 | 20429990450 |
| 18 | 91348096963 |
| 19 | 409110897122 |
| 20 | 1834954888618 |
| 21 | 8241277167236 |
| 22 | 37059369415102 |
[1,2,7,26,103,422,1768,7520,32335,140174,611530, 2681516,11807683,52177166,231262945,1027703054, 4577477065,20429990450,91348096963,409110897122, 1834954888618,8241277167236,37059369415102] |