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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 20 |
| 3 | 73 |
| 4 | 265 |
| 5 | 961 |
| 6 | 3577 |
| 7 | 13593 |
| 8 | 53529 |
| 9 | 213529 |
| 10 | 850181 |
| 11 | 3404741 |
| 12 | 13593109 |
| 13 | 54297057 |
| 14 | 217165509 |
| 15 | 868360921 |
[1,5,20,73,265,961,3577,13593,53529,213529,850181, 3404741,13593109,54297057,217165509,868360921] |