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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 92 |
| 4 | 1304 |
| 5 | 20198 |
| 6 | 332520 |
| 7 | 5703724 |
| 8 | 100847976 |
| 9 | 1824927697 |
| 10 | 33634879304 |
| 11 | 629201396744 |
| 12 | 11915930584384 |
| 13 | 228010216559592 |
| 14 | 4401559021963488 |
| 15 | 85616787777724400 |
| 16 | 1676436841812675760 |
| 17 | 33017479163392717192 |
| 18 | 653643628799220208104 |
| 19 | 12999812350464606307796 |
[0,1,8,92,1304,20198,332520,5703724,100847976, 1824927697,33634879304,629201396744, 11915930584384,228010216559592,4401559021963488, 85616787777724400,1676436841812675760, 33017479163392717192,653643628799220208104, 12999812350464606307796] |