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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 43 |
| 4 | 179 |
| 5 | 771 |
| 6 | 3395 |
| 7 | 15171 |
| 8 | 68515 |
| 9 | 311907 |
| 10 | 1428835 |
| 11 | 6578531 |
| 12 | 30414435 |
| 13 | 141105251 |
| 14 | 656588899 |
| 15 | 3063038051 |
| 16 | 14321092195 |
| 17 | 67088405091 |
| 18 | 314825048675 |
| 19 | 1479654425187 |
| 20 | 6963888239203 |
| 21 | 32815960756835 |
| 22 | 154813864252003 |
[1,3,11,43,179,771,3395,15171,68515,311907, 1428835,6578531,30414435,141105251,656588899, 3063038051,14321092195,67088405091,314825048675, 1479654425187,6963888239203,32815960756835, 154813864252003] |