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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 21 |
| 6 | 61 |
| 7 | 211 |
| 8 | 1401 |
| 9 | 8065 |
| 10 | 37241 |
| 11 | 240021 |
| 12 | 1997821 |
| 13 | 13856701 |
| 14 | 94418325 |
| 15 | 874328911 |
| 16 | 8304303281 |
| 17 | 69158458881 |
| 18 | 658339599601 |
| 19 | 7454839614985 |
| 20 | 78224066633781 |
| 21 | 805961931388741 |
| 22 | 9828080719704941 |
| 23 | 124199805022959051 |
| 24 | 1466207770078872745 |
[1,1,1,1,5,21,61,211,1401,8065,37241,240021, 1997821,13856701,94418325,874328911,8304303281, 69158458881,658339599601,7454839614985, 78224066633781,805961931388741,9828080719704941, 124199805022959051,1466207770078872745] |