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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | -7 |
| 3 | -118 |
| 4 | -399 |
| 5 | 0 |
| 6 | 7849 |
| 7 | 61318 |
| 8 | 357857 |
| 9 | 1894076 |
| 10 | 9665625 |
| 11 | 48667074 |
| 12 | 243891793 |
| 13 | 1220331832 |
| 14 | 6102977801 |
| 15 | 30516818750 |
| 16 | 152586842049 |
| 17 | 762938033268 |
| 18 | 3814695376057 |
| 19 | 19073483852026 |
| 20 | 95367428440625 |
[1,4,-7,-118,-399,0,7849,61318,357857,1894076, 9665625,48667074,243891793,1220331832,6102977801, 30516818750,152586842049,762938033268, 3814695376057,19073483852026,95367428440625] |