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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 8 |
| 3 | 87 |
| 4 | 497 |
| 5 | 2066 |
| 6 | 17674 |
| 7 | 81537 |
| 8 | 800040 |
| 9 | 3877847 |
| 10 | 39636760 |
| 11 | 197167116 |
| 12 | 2044535652 |
| 13 | 10266459303 |
| 14 | 107207411996 |
| 15 | 541084890084 |
| 16 | 5674279900642 |
| 17 | 28738733251005 |
| 18 | 302282496834886 |
| 19 | 1535249200603440 |
| 20 | 16185756541061498 |
[0,8,87,497,2066,17674,81537,800040,3877847, 39636760,197167116,2044535652,10266459303, 107207411996,541084890084,5674279900642, 28738733251005,302282496834886,1535249200603440, 16185756541061498] |