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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 16 |
| 3 | 64 |
| 4 | 229 |
| 5 | 592 |
| 6 | -224 |
| 7 | -18176 |
| 8 | -175655 |
| 9 | -1265732 |
| 10 | -7914560 |
| 11 | -44970752 |
| 12 | -236014307 |
| 13 | -1145932664 |
| 14 | -5086940240 |
| 15 | -19929220352 |
| 16 | -61944816911 |
| 17 | -81359219468 |
| 18 | 858917862064 |
| 19 | 10785877546432 |
| 20 | 84667993188757 |
| 21 | 555461238134080 |
| 22 | 3268576565244544 |
| 23 | 17688312222825472 |
| 24 | 88631554966652233 |
| 25 | 408731119650234796 |
[1,4,16,64,229,592,-224,-18176,-175655,-1265732, -7914560,-44970752,-236014307,-1145932664, -5086940240,-19929220352,-61944816911, -81359219468,858917862064,10785877546432, 84667993188757,555461238134080,3268576565244544, 17688312222825472,88631554966652233, 408731119650234796] |