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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 78 |
| 4 | 1278 |
| 5 | 9498 |
| 6 | 47331 |
| 7 | 175952 |
| 8 | 545764 |
| 9 | 1461672 |
| 10 | 3507553 |
| 11 | 7701638 |
| 12 | 15773526 |
| 13 | 30375194 |
| 14 | 55695587 |
| 15 | 97777392 |
| 16 | 165310348 |
| 17 | 270478344 |
| 18 | 430196181 |
| 19 | 666685134 |
| 20 | 1010083690 |
| 21 | 1498720098 |
| 22 | 2182544223 |
[0,1,78,1278,9498,47331,175952,545764,1461672, 3507553,7701638,15773526,30375194,55695587, 97777392,165310348,270478344,430196181,666685134, 1010083690,1498720098,2182544223] |