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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 12 |
| 5 | 26 |
| 6 | 53 |
| 7 | 110 |
| 8 | 231 |
| 9 | 483 |
| 10 | 1013 |
| 11 | 2125 |
| 12 | 4445 |
| 13 | 9307 |
| 14 | 19487 |
| 15 | 40802 |
| 16 | 85439 |
| 17 | 178910 |
| 18 | 374622 |
| 19 | 784426 |
| 20 | 1642522 |
[1,2,6,12,26,53,110,231,483,1013,2125,4445,9307, 19487,40802,85439,178910,374622,784426,1642522] |