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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 8 |
| 4 | 32 |
| 5 | 448 |
| 6 | 2240 |
| 7 | 64512 |
| 8 | 556032 |
| 9 | 33521664 |
| 10 | 553615360 |
| 11 | 68717379584 |
| 12 | 2233380896768 |
| 13 | 562949684985856 |
| 14 | 36310271727239168 |
| 15 | 18446744004990074880 |
| 16 | 2370406613402957905920 |
| 17 | 2417851639194073977323520 |
| 18 | 620178945462269582252179456 |
| 19 | 1267650600228193372699684241408 |
[0,1,8,32,448,2240,64512,556032,33521664, 553615360,68717379584,2233380896768, 562949684985856,36310271727239168, 18446744004990074880,2370406613402957905920, 2417851639194073977323520, 620178945462269582252179456, 1267650600228193372699684241408] |