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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 6 |
| 2 | 34 |
| 3 | 180 |
| 4 | 876 |
| 5 | 3816 |
| 6 | 14136 |
| 7 | 39024 |
| 8 | 36240 |
| 9 | -406944 |
| 10 | -3093984 |
| 11 | -10425024 |
| 12 | 5517504 |
| 13 | 283305600 |
| 14 | 1556378496 |
| 15 | 1405714176 |
| 16 | -38257069824 |
| 17 | -274525272576 |
| 18 | -346411261440 |
| 19 | 7804442244096 |
| 20 | 59990281399296 |
| 21 | 47763998631936 |
| 22 | -2233007826978816 |
| 23 | -15499662901678080 |
[1,6,34,180,876,3816,14136,39024,36240,-406944, -3093984,-10425024,5517504,283305600,1556378496, 1405714176,-38257069824,-274525272576, -346411261440,7804442244096,59990281399296, 47763998631936,-2233007826978816, -15499662901678080] |