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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 7 |
| 4 | 25 |
| 5 | 101 |
| 6 | 366 |
| 7 | 1555 |
| 8 | 7099 |
| 9 | 34627 |
| 10 | 184033 |
| 11 | 1059972 |
| 12 | 6425992 |
| 13 | 41266681 |
| 14 | 280938451 |
| 15 | 2009636335 |
| 16 | 15025372685 |
| 17 | 117386912433 |
| 18 | 956458929950 |
| 19 | 8104399834719 |
| 20 | 71244441818927 |
| 21 | 648761935841876 |
| 22 | 6110827367541999 |
| 23 | 59454153443971106 |
| 24 | 596654820386392152 |
[1,7,25,101,366,1555,7099,34627,184033,1059972, 6425992,41266681,280938451,2009636335,15025372685, 117386912433,956458929950,8104399834719, 71244441818927,648761935841876,6110827367541999, 59454153443971106,596654820386392152] |