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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 47 |
| 5 | 246 |
| 6 | 1602 |
| 7 | 11481 |
| 8 | 95503 |
| 9 | 508150 |
| 10 | 3436358 |
| 11 | 21822351 |
| 12 | 153741722 |
| 13 | 1047906107 |
| 14 | 7987668041 |
| 15 | 57017211075 |
| 16 | 456108767423 |
| 17 | 3047668772102 |
| 18 | 22857224364630 |
| 19 | 163293406206195 |
| 20 | 1236484989279502 |
| 21 | 9040845014760345 |
| 22 | 70057104400850471 |
| 23 | 517521934394653205 |
[1,1,3,10,47,246,1602,11481,95503,508150,3436358, 21822351,153741722,1047906107,7987668041, 57017211075,456108767423,3047668772102, 22857224364630,163293406206195,1236484989279502, 9040845014760345,70057104400850471, 517521934394653205] |