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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | -4 |
| 6 | 8 |
| 7 | -16 |
| 8 | 32 |
| 9 | -54 |
| 10 | 108 |
| 11 | -184 |
| 12 | 368 |
| 13 | -628 |
| 14 | 1296 |
| 15 | -2160 |
| 16 | 4610 |
| 17 | -7708 |
| 18 | 15848 |
| 19 | -27592 |
| 20 | 58316 |
| 21 | -98496 |
| 22 | 207576 |
| 23 | -364720 |
| 24 | 756872 |
| 25 | -1341970 |
| 26 | 2778300 |
| 27 | -4918536 |
| 28 | 10443152 |
| 29 | -18512788 |
| 30 | 37698416 |
| 31 | -69273664 |
| 32 | 145105952 |
| 33 | -258224544 |
| 34 | 534996900 |
| 35 | -981494752 |
| 36 | 2020011290 |
| 37 | -3714566308 |
| 38 | 7614288360 |
[2,0,0,2,-4,8,-16,32,-54,108,-184,368,-628,1296, -2160,4610,-7708,15848,-27592,58316,-98496,207576, -364720,756872,-1341970,2778300,-4918536,10443152, -18512788,37698416,-69273664,145105952,-258224544, 534996900,-981494752,2020011290,-3714566308, 7614288360] |