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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 55 |
| 3 | 5525 |
| 4 | 22140 |
| 5 | 93665 |
| 6 | 173880 |
| 7 | 1378160 |
| 8 | 3822225 |
| 9 | 19096385 |
| 10 | 21413400 |
| 11 | 58695560 |
| 12 | 81575625 |
| 13 | 161553785 |
| 14 | 170986800 |
| 15 | 295372960 |
| 16 | 555371185 |
| 17 | 5595682560 |
| 18 | 6032742625 |
| 19 | 21341334000 |
| 20 | 46478345185 |
| 21 | 94121656560 |
| 22 | 96947076625 |
[1,55,5525,22140,93665,173880,1378160,3822225, 19096385,21413400,58695560,81575625,161553785, 170986800,295372960,555371185,5595682560, 6032742625,21341334000,46478345185,94121656560, 96947076625] |