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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 45 |
| 5 | 197 |
| 6 | 903 |
| 7 | 4279 |
| 8 | 20793 |
| 9 | 103049 |
| 10 | 518859 |
| 11 | 2646723 |
| 12 | 13648869 |
| 13 | 71039373 |
| 14 | 372693519 |
| 15 | 1968801519 |
| 16 | 10463578353 |
| 17 | 55909013009 |
| 18 | 300159426963 |
| 19 | 1618362158587 |
| 20 | 8759309660445 |
| 21 | 47574827600981 |
| 22 | 259215937709463 |
| 23 | 1416461675464871 |
[1,1,3,11,45,197,903,4279,20793,103049,518859, 2646723,13648869,71039373,372693519,1968801519, 10463578353,55909013009,300159426963, 1618362158587,8759309660445,47574827600981, 259215937709463,1416461675464871] |