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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 48 |
| 3 | 10 |
| 4 | 141 |
| 5 | 1590 |
| 6 | 3282 |
| 7 | 27915 |
| 8 | 246700 |
| 9 | 1055145 |
| 10 | 7129209 |
| 11 | 56638725 |
| 12 | 310179586 |
| 13 | 2031847146 |
| 14 | 14612093372 |
| 15 | 88989021585 |
| 16 | 580066345101 |
| 17 | 3961760881902 |
| 18 | 25211203481003 |
| 19 | 164396604060820 |
| 20 | 1096627513193338 |
| 21 | 7101386707723193 |
[0,48,10,141,1590,3282,27915,246700,1055145, 7129209,56638725,310179586,2031847146,14612093372, 88989021585,580066345101,3961760881902, 25211203481003,164396604060820,1096627513193338, 7101386707723193] |