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| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 4 |
| 6 | 10 |
| 7 | 22 |
| 8 | 55 |
| 9 | 194 |
| 10 | 784 |
| 11 | 4435 |
| 12 | 26044 |
| 13 | 168125 |
| 14 | 1273021 |
| 15 | 11736308 |
| 16 | 129333849 |
| 17 | 1686140456 |
| 18 | 25343021943 |
| 19 | 443460444588 |
[1,4,10,22,55,194,784,4435,26044,168125,1273021, 11736308,129333849,1686140456,25343021943, 443460444588] |