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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 513 |
| 3 | 19684 |
| 4 | 262656 |
| 5 | 1953126 |
| 6 | 10097892 |
| 7 | 40353608 |
| 8 | 134479872 |
| 9 | 387440172 |
| 10 | 1001953638 |
| 11 | 2357947692 |
| 12 | 5170120704 |
| 13 | 10604499374 |
| 14 | 20701400904 |
| 15 | 38445332184 |
| 16 | 68853694464 |
| 17 | 118587876498 |
| 18 | 198756808236 |
| 19 | 322687697780 |
| 20 | 513000262656 |
| 21 | 794320419872 |
| 22 | 1209627165996 |
| 23 | 1801152661464 |
| 24 | 2647101800448 |
[1,513,19684,262656,1953126,10097892,40353608, 134479872,387440172,1001953638,2357947692, 5170120704,10604499374,20701400904,38445332184, 68853694464,118587876498,198756808236, 322687697780,513000262656,794320419872, 1209627165996,1801152661464,2647101800448] |