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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 47 |
| 4 | 211 |
| 5 | 1342 |
| 6 | 7370 |
| 7 | 42704 |
| 8 | 242626 |
| 9 | 1388464 |
| 10 | 7923848 |
| 11 | 45270764 |
| 12 | 258521500 |
| 13 | 1476606232 |
| 14 | 8433200480 |
| 15 | 48165787136 |
| 16 | 275090964088 |
| 17 | 1571151179728 |
| 18 | 8973415333520 |
| 19 | 51250537925936 |
| 20 | 292710757678096 |
| 21 | 1671780007210336 |
[1,5,47,211,1342,7370,42704,242626,1388464, 7923848,45270764,258521500,1476606232,8433200480, 48165787136,275090964088,1571151179728, 8973415333520,51250537925936,292710757678096, 1671780007210336] |