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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 0 |
| 3 | 3 |
| 4 | 4 |
| 5 | 15 |
| 6 | 54 |
| 7 | 245 |
| 8 | 1240 |
| 9 | 7119 |
| 10 | 45290 |
| 11 | 317229 |
| 12 | 2423268 |
| 13 | 20055607 |
| 14 | 178747646 |
| 15 | 1706919045 |
| 16 | 17386518448 |
| 17 | 188166282399 |
| 18 | 2156226542802 |
| 19 | 26081233464413 |
| 20 | 332076574410940 |
| 21 | 4439536794401415 |
| 22 | 62178531797006438 |
| 23 | 910433903838620853 |
| 24 | 13910405388847664904 |
[1,-1,0,3,4,15,54,245,1240,7119,45290,317229, 2423268,20055607,178747646,1706919045,17386518448, 188166282399,2156226542802,26081233464413, 332076574410940,4439536794401415, 62178531797006438,910433903838620853, 13910405388847664904] |