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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 15 |
| 5 | 158 |
| 6 | 3355 |
| 7 | 93708 |
| 8 | 3535448 |
| 9 | 170816680 |
| 10 | 10307577384 |
| 11 | 759439940230 |
| 12 | 67095584693434 |
| 13 | 7001532238614324 |
| 14 | 851997581131397870 |
| 15 | 119582892039683711842 |
| 16 | 19176016845387328919910 |
| 17 | 3484133398830462852182192 |
| 18 | 712017802878894004029129622 |
| 19 | 162597177988359237252433594350 |
[1,0,1,1,15,158,3355,93708,3535448,170816680, 10307577384,759439940230,67095584693434, 7001532238614324,851997581131397870, 119582892039683711842,19176016845387328919910, 3484133398830462852182192, 712017802878894004029129622, 162597177988359237252433594350] |