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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 3 |
| 4 | 16 |
| 5 | 125 |
| 6 | 756 |
| 7 | 7567 |
| 8 | 85968 |
| 9 | 994905 |
| 10 | 14373460 |
| 11 | 225366251 |
| 12 | 3800667960 |
| 13 | 72169966453 |
| 14 | 1469546796732 |
| 15 | 32150706096615 |
| 16 | 760806334538656 |
| 17 | 19142440567996721 |
| 18 | 512272692571487652 |
| 19 | 14560087915617858883 |
| 20 | 436598686303562722440 |
| 21 | 13796641165956117509901 |
[1,0,2,3,16,125,756,7567,85968,994905,14373460, 225366251,3800667960,72169966453,1469546796732, 32150706096615,760806334538656,19142440567996721, 512272692571487652,14560087915617858883, 436598686303562722440,13796641165956117509901] |