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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | -1 |
| 4 | 2 |
| 5 | -4 |
| 6 | 10 |
| 7 | -24 |
| 8 | 60 |
| 9 | -156 |
| 10 | 415 |
| 11 | -1126 |
| 12 | 3099 |
| 13 | -8630 |
| 14 | 24266 |
| 15 | -68794 |
| 16 | 196433 |
| 17 | -564358 |
| 18 | 1630219 |
| 19 | -4731681 |
| 20 | 13792091 |
| 21 | -40355104 |
| 22 | 118483124 |
| 23 | -348949952 |
| 24 | 1030616162 |
| 25 | -3051771509 |
| 26 | 9058068276 |
| 27 | -26944245623 |
| 28 | 80310259922 |
| 29 | -239820489258 |
| 30 | 717388363313 |
| 31 | -2149431491830 |
| 32 | 6449821500433 |
[1,1,-1,2,-4,10,-24,60,-156,415,-1126,3099,-8630, 24266,-68794,196433,-564358,1630219,-4731681, 13792091,-40355104,118483124,-348949952, 1030616162,-3051771509,9058068276,-26944245623, 80310259922,-239820489258,717388363313, -2149431491830,6449821500433] |