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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 2 |
| 6 | 14 |
| 7 | 102 |
| 8 | 828 |
| 9 | 7522 |
| 10 | 75706 |
| 11 | 836622 |
| 12 | 10073824 |
| 13 | 131300266 |
| 14 | 1841921270 |
| 15 | 27673138086 |
| 16 | 443343106468 |
| 17 | 7544813993618 |
| 18 | 135925854199186 |
| 19 | 2584491212811038 |
| 20 | 51722014716352136 |
| 21 | 1086739983701035418 |
| 22 | 23919225571408768782 |
| 23 | 550360567615450589302 |
[1,1,0,0,0,2,14,102,828,7522,75706,836622, 10073824,131300266,1841921270,27673138086, 443343106468,7544813993618,135925854199186, 2584491212811038,51722014716352136, 1086739983701035418,23919225571408768782, 550360567615450589302] |