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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 39 |
| 6 | 193 |
| 7 | 1135 |
| 8 | 7585 |
| 9 | 57055 |
| 10 | 476161 |
| 11 | 4366399 |
| 12 | 43627393 |
| 13 | 471693439 |
| 14 | 5486186497 |
| 15 | 68296367871 |
| 16 | 906012795393 |
| 17 | 12758750871039 |
| 18 | 190081374027777 |
| 19 | 2986828127798271 |
| 20 | 49367131036252161 |
| 21 | 856162355062638591 |
| 22 | 15545263081776742401 |
| 23 | 294905583408022810623 |
[1,1,1,3,9,39,193,1135,7585,57055,476161,4366399, 43627393,471693439,5486186497,68296367871, 906012795393,12758750871039,190081374027777, 2986828127798271,49367131036252161, 856162355062638591,15545263081776742401, 294905583408022810623] |