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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 1 |
| 7 | 3 |
| 8 | 17 |
| 9 | 73 |
| 10 | 241 |
| 11 | 661 |
| 12 | 1585 |
| 13 | 3461 |
| 14 | 7285 |
| 15 | 16231 |
| 16 | 41921 |
| 17 | 124577 |
| 18 | 389233 |
| 19 | 1186617 |
| 20 | 3423201 |
| 21 | 9327801 |
| 22 | 24355849 |
| 23 | 62489483 |
| 24 | 162336209 |
| 25 | 437155705 |
| 26 | 1226390417 |
| 27 | 3534342301 |
| 28 | 10244919841 |
| 29 | 29383388701 |
| 30 | 82792942045 |
[1,1,1,1,1,1,3,17,73,241,661,1585,3461,7285,16231, 41921,124577,389233,1186617,3423201,9327801, 24355849,62489483,162336209,437155705,1226390417, 3534342301,10244919841,29383388701,82792942045] |