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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 13 |
| 5 | 46 |
| 6 | 254 |
| 7 | 2335 |
| 8 | 37679 |
| 9 | 1036686 |
| 10 | 47847128 |
| 11 | 3666918138 |
| 12 | 462476814296 |
| 13 | 95511722707577 |
| 14 | 32204769674856063 |
| 15 | 17694312704564808047 |
| 16 | 15825068959028242214319 |
[1,3,6,13,46,254,2335,37679,1036686,47847128, 3666918138,462476814296,95511722707577, 32204769674856063,17694312704564808047, 15825068959028242214319] |