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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 78 |
| 4 | 1022 |
| 5 | 13197 |
| 6 | 150777 |
| 7 | 1442764 |
| 8 | 11408125 |
| 9 | 75393424 |
| 10 | 424992394 |
| 11 | 2086954916 |
| 12 | 9097630767 |
| 13 | 35775808290 |
| 14 | 128617512596 |
| 15 | 427443971156 |
| 16 | 1325376633243 |
| 17 | 3864035126505 |
| 18 | 10661515466643 |
| 19 | 27995060608622 |
| 20 | 70289431296342 |
[1,7,78,1022,13197,150777,1442764,11408125, 75393424,424992394,2086954916,9097630767, 35775808290,128617512596,427443971156, 1325376633243,3864035126505,10661515466643, 27995060608622,70289431296342] |