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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 16 |
| 2 | 127 |
| 3 | 1008 |
| 4 | 8000 |
| 5 | 63492 |
| 6 | 503904 |
| 7 | 3999232 |
| 8 | 31739888 |
| 9 | 251903488 |
| 10 | 1999230976 |
| 11 | 15866888256 |
| 12 | 125927492096 |
| 13 | 999423012864 |
| 14 | 7931916549888 |
| 15 | 62951622430720 |
| 16 | 499615287394304 |
| 17 | 3965194632954880 |
| 18 | 31469750573916160 |
| 19 | 249759543441752064 |
| 20 | 1982215569002196992 |
| 21 | 15731845549721911296 |
[2,16,127,1008,8000,63492,503904,3999232,31739888, 251903488,1999230976,15866888256,125927492096, 999423012864,7931916549888,62951622430720, 499615287394304,3965194632954880, 31469750573916160,249759543441752064, 1982215569002196992,15731845549721911296] |