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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 23 |
| 2 | 152 |
| 3 | 1107 |
| 4 | 8611 |
| 5 | 70478 |
| 6 | 1793210 |
| 7 | 5156463 |
| 8 | 45470645 |
| 9 | 2074530409 |
| 10 | 11397691034 |
| 11 | 33578243459 |
| 12 | 639583252186 |
[1,23,152,1107,8611,70478,1793210,5156463, 45470645,2074530409,11397691034,33578243459, 639583252186] |