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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 24 |
| 3 | 96 |
| 4 | 168 |
| 5 | 1200 |
| 6 | 3960 |
| 7 | 16128 |
| 8 | 66888 |
| 9 | 259152 |
| 10 | 1052184 |
| 11 | 4195488 |
| 12 | 16759272 |
| 13 | 67158000 |
| 14 | 268359864 |
| 15 | 1073772096 |
| 16 | 4295178888 |
| 17 | 17179113360 |
| 18 | 68720897880 |
| 19 | 274876666848 |
| 20 | 1099509663528 |
| 21 | 4398057364272 |
| 22 | 17592161341944 |
| 23 | 70368774872448 |
| 24 | 281474983436232 |
| 25 | 1125899763886800 |
[0,24,96,168,1200,3960,16128,66888,259152,1052184, 4195488,16759272,67158000,268359864,1073772096, 4295178888,17179113360,68720897880,274876666848, 1099509663528,4398057364272,17592161341944, 70368774872448,281474983436232,1125899763886800] |