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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 9 |
| 6 | 16 |
| 7 | 93 |
| 8 | 367 |
| 9 | 2220 |
| 10 | 13167 |
| 11 | 126326 |
| 12 | 1163166 |
| 13 | 15908600 |
| 14 | 209043350 |
| 15 | 4432902382 |
| 16 | 88370483688 |
[1,1,1,3,9,16,93,367,2220,13167,126326,1163166, 15908600,209043350,4432902382,88370483688] |