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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 19 |
| 4 | 37 |
| 5 | 127 |
| 6 | 323 |
| 7 | 763 |
| 8 | 2121 |
| 9 | 5557 |
| 10 | 14031 |
| 11 | 37065 |
| 12 | 97027 |
| 13 | 250371 |
| 14 | 653707 |
| 15 | 1706245 |
| 16 | 4431885 |
| 17 | 11544027 |
| 18 | 30085525 |
| 19 | 78290135 |
| 20 | 203852347 |
| 21 | 530958219 |
| 22 | 1382353401 |
| 23 | 3599332477 |
| 24 | 9373032927 |
| 25 | 24405570561 |
| 26 | 63547912011 |
| 27 | 165475162027 |
| 28 | 430875964651 |
[1,9,19,37,127,323,763,2121,5557,14031,37065, 97027,250371,653707,1706245,4431885,11544027, 30085525,78290135,203852347,530958219,1382353401, 3599332477,9373032927,24405570561,63547912011, 165475162027,430875964651] |