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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 5986 |
| 4 | 70930 |
| 5 | 684823 |
| 6 | 4554895 |
| 7 | 25784285 |
| 8 | 124544429 |
| 9 | 541577200 |
| 10 | 2142536303 |
| 11 | 7874214410 |
| 12 | 27111618590 |
| 13 | 88375985276 |
| 14 | 274361915435 |
| 15 | 816223635550 |
| 16 | 2336827590285 |
| 17 | 6464455999320 |
| 18 | 17332496822417 |
| 19 | 45169505417075 |
| 20 | 114679191847782 |
| 21 | 284240995638700 |
| 22 | 689000215557685 |
[1,0,0,5986,70930,684823,4554895,25784285, 124544429,541577200,2142536303,7874214410, 27111618590,88375985276,274361915435,816223635550, 2336827590285,6464455999320,17332496822417, 45169505417075,114679191847782,284240995638700, 689000215557685] |