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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | 0 |
| 6 | 26 |
| 7 | 84 |
| 8 | 950 |
| 9 | 6000 |
| 10 | 62522 |
| 11 | 556116 |
| 12 | 6259598 |
| 13 | 69319848 |
| 14 | 874356338 |
| 15 | 11384093196 |
| 16 | 161462123894 |
| 17 | 2397736692144 |
| 18 | 37994808171962 |
| 19 | 631767062124564 |
| 20 | 11088109048500158 |
| 21 | 203828700127054008 |
| 22 | 3928762035148317314 |
| 23 | 79079452776283889820 |
| 24 | 1661265965479375937030 |
| 25 | 36332908076071038467520 |
| 26 | 826376466514358722894154 |
[1,0,0,0,2,0,26,84,950,6000,62522,556116,6259598, 69319848,874356338,11384093196,161462123894, 2397736692144,37994808171962,631767062124564, 11088109048500158,203828700127054008, 3928762035148317314,79079452776283889820, 1661265965479375937030,36332908076071038467520, 826376466514358722894154] |