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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | -5 |
| 3 | -25 |
| 4 | -100 |
| 5 | -375 |
| 6 | -1375 |
| 7 | -5000 |
| 8 | -18125 |
| 9 | -65625 |
| 10 | -237500 |
| 11 | -859375 |
| 12 | -3109375 |
| 13 | -11250000 |
| 14 | -40703125 |
| 15 | -147265625 |
| 16 | -532812500 |
| 17 | -1927734375 |
| 18 | -6974609375 |
| 19 | -25234375000 |
| 20 | -91298828125 |
| 21 | -330322265625 |
| 22 | -1195117187500 |
| 23 | -4323974609375 |
| 24 | -15644287109375 |
| 25 | -56601562500000 |
[1,0,-5,-25,-100,-375,-1375,-5000,-18125,-65625, -237500,-859375,-3109375,-11250000,-40703125, -147265625,-532812500,-1927734375,-6974609375, -25234375000,-91298828125,-330322265625, -1195117187500,-4323974609375,-15644287109375, -56601562500000] |