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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 2 |
| 2 | 26 |
| 3 | 242 |
| 4 | 2162 |
| 5 | 20162 |
| 6 | 201602 |
| 7 | 2177282 |
| 8 | 25401602 |
| 9 | 319334402 |
| 10 | 4311014402 |
| 11 | 62270208002 |
| 12 | 958961203202 |
| 13 | 15692092416002 |
| 14 | 271996268544002 |
| 15 | 4979623993344002 |
| 16 | 96035605585920002 |
| 17 | 1946321606541312002 |
| 18 | 41359334139002880002 |
| 19 | 919636959090769920002 |
| 20 | 21356013827774545920002 |
[0,2,26,242,2162,20162,201602,2177282,25401602, 319334402,4311014402,62270208002,958961203202, 15692092416002,271996268544002,4979623993344002, 96035605585920002,1946321606541312002, 41359334139002880002,919636959090769920002, 21356013827774545920002] |