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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 84 |
| 4 | 2880 |
| 5 | 155152 |
| 6 | 11947072 |
| 7 | 1240929984 |
| 8 | 166862665728 |
| 9 | 28164532992256 |
| 10 | 5825137200342016 |
| 11 | 1447885245123609600 |
| 12 | 425631502990107721728 |
| 13 | 146006164524789598523392 |
| 14 | 57780315705196065420230656 |
| 15 | 26120433169446248117938667520 |
| 16 | 13373554434110899828789859057664 |
[0,1,4,84,2880,155152,11947072,1240929984, 166862665728,28164532992256,5825137200342016, 1447885245123609600,425631502990107721728, 146006164524789598523392, 57780315705196065420230656, 26120433169446248117938667520, 13373554434110899828789859057664] |