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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 30 |
| 3 | 200 |
| 4 | 1550 |
| 5 | 14000 |
| 6 | 144500 |
| 7 | 1662500 |
| 8 | 20952500 |
| 9 | 286437500 |
| 10 | 4221312500 |
| 11 | 66703437500 |
| 12 | 1124194062500 |
| 13 | 20109785937500 |
| 14 | 380209901562500 |
| 15 | 7571141773437500 |
| 16 | 158312671414062500 |
| 17 | 3466819503710937500 |
| 18 | 79316483272226562500 |
| 19 | 1891747084452148437500 |
| 20 | 46942864023040039062500 |
[1,5,30,200,1550,14000,144500,1662500,20952500, 286437500,4221312500,66703437500,1124194062500, 20109785937500,380209901562500,7571141773437500, 158312671414062500,3466819503710937500, 79316483272226562500,1891747084452148437500, 46942864023040039062500] |