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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 24 |
| 5 | 99 |
| 6 | 416 |
| 7 | 1854 |
| 8 | 8407 |
| 9 | 38970 |
| 10 | 182742 |
| 11 | 866442 |
| 12 | 4140607 |
| 13 | 19925401 |
| 14 | 96430625 |
| 15 | 469005432 |
| 16 | 2290860538 |
| 17 | 11232074043 |
| 18 | 55255074216 |
| 19 | 272634835875 |
| 20 | 1348823736479 |
| 21 | 6689314884962 |
| 22 | 33247860759418 |
| 23 | 165583649067958 |
| 24 | 826170069700588 |
| 25 | 4129098732200830 |
[1,2,7,24,99,416,1854,8407,38970,182742,866442, 4140607,19925401,96430625,469005432,2290860538, 11232074043,55255074216,272634835875, 1348823736479,6689314884962,33247860759418, 165583649067958,826170069700588,4129098732200830] |