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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 15 |
| 3 | 150 |
| 4 | 1250 |
| 5 | 9375 |
| 6 | 65625 |
| 7 | 437500 |
| 8 | 2812500 |
| 9 | 17578125 |
| 10 | 107421875 |
| 11 | 644531250 |
| 12 | 3808593750 |
| 13 | 22216796875 |
| 14 | 128173828125 |
| 15 | 732421875000 |
| 16 | 4150390625000 |
| 17 | 23345947265625 |
| 18 | 130462646484375 |
| 19 | 724792480468750 |
| 20 | 4005432128906250 |
[0,1,15,150,1250,9375,65625,437500,2812500, 17578125,107421875,644531250,3808593750, 22216796875,128173828125,732421875000, 4150390625000,23345947265625,130462646484375, 724792480468750,4005432128906250] |