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| n | a(n) |
|---|---|
| 2 | 2 |
| 3 | 5 |
| 4 | 12 |
| 5 | 30 |
| 6 | 77 |
| 7 | 200 |
| 8 | 522 |
| 9 | 1365 |
| 10 | 3572 |
| 11 | 9350 |
| 12 | 24477 |
| 13 | 64080 |
| 14 | 167762 |
| 15 | 439205 |
| 16 | 1149852 |
| 17 | 3010350 |
| 18 | 7881197 |
| 19 | 20633240 |
[2,5,12,30,77,200,522,1365,3572,9350,24477,64080, 167762,439205,1149852,3010350,7881197,20633240] |