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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 68 |
| 3 | 1107 |
| 4 | 8224 |
| 5 | 39125 |
| 6 | 140076 |
| 7 | 411943 |
| 8 | 1048832 |
| 9 | 2391849 |
| 10 | 5000500 |
| 11 | 9744251 |
| 12 | 17916768 |
| 13 | 31375357 |
| 14 | 52708124 |
| 15 | 85431375 |
| 16 | 134219776 |
| 17 | 205171793 |
| 18 | 306112932 |
| 19 | 446939299 |
| 20 | 640004000 |
| 21 | 900548901 |
| 22 | 1247184268 |
| 23 | 1702418807 |
| 24 | 2293242624 |
[0,1,68,1107,8224,39125,140076,411943,1048832, 2391849,5000500,9744251,17916768,31375357, 52708124,85431375,134219776,205171793,306112932, 446939299,640004000,900548901,1247184268, 1702418807,2293242624] |