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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 15 |
| 4 | 296 |
| 5 | 10965 |
| 6 | 609864 |
| 7 | 47880595 |
| 8 | 5047886640 |
| 9 | 688359502089 |
| 10 | 117929734950320 |
| 11 | 24798753695076471 |
| 12 | 6280419381186155160 |
| 13 | 1885582606127524251805 |
| 14 | 662239984799385248609976 |
| 15 | 268999138538324585872798395 |
| 16 | 125133475474486312764311243744 |
| 17 | 66091677106419135401506827779985 |
[1,0,15,296,10965,609864,47880595,5047886640, 688359502089,117929734950320,24798753695076471, 6280419381186155160,1885582606127524251805, 662239984799385248609976, 268999138538324585872798395, 125133475474486312764311243744, 66091677106419135401506827779985] |