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| n | a(n) |
|---|---|
| 1 | 12 |
| 2 | 20 |
| 3 | 272 |
| 4 | 1096 |
| 5 | 8426 |
| 6 | 57426 |
| 7 | 367803 |
| 8 | 2845485 |
| 9 | 20018093 |
| 10 | 150949412 |
| 11 | 1177693211 |
| 12 | 8931183872 |
| 13 | 71580272704 |
| 14 | 565415811806 |
| 15 | 4521022021693 |
| 16 | 36638382301846 |
| 17 | 294985330832346 |
| 18 | 2401765918095904 |
| 19 | 19540533876057217 |
| 20 | 159156617785973772 |
[12,20,272,1096,8426,57426,367803,2845485, 20018093,150949412,1177693211,8931183872, 71580272704,565415811806,4521022021693, 36638382301846,294985330832346,2401765918095904, 19540533876057217,159156617785973772] |