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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 12 |
| 3 | 98 |
| 4 | 988 |
| 5 | 10872 |
| 6 | 129520 |
| 7 | 1609176 |
| 8 | 20786804 |
| 9 | 274792342 |
| 10 | 3719296036 |
| 11 | 51119572738 |
| 12 | 712918642042 |
| 13 | 10055531355652 |
| 14 | 143287150725298 |
| 15 | 2058368140071146 |
| 16 | 29796314629826814 |
| 17 | 434051906728752164 |
| 18 | 6359063811707227298 |
| 19 | 93635249115751389952 |
| 20 | 1385028309353547034876 |
[1,2,12,98,988,10872,129520,1609176,20786804, 274792342,3719296036,51119572738,712918642042, 10055531355652,143287150725298,2058368140071146, 29796314629826814,434051906728752164, 6359063811707227298,93635249115751389952, 1385028309353547034876] |