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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | 50 |
| 3 | 350 |
| 4 | 2500 |
| 5 | 17500 |
| 6 | 125000 |
| 7 | 875000 |
| 8 | 6250000 |
| 9 | 43750000 |
| 10 | 312500000 |
| 11 | 2187500000 |
| 12 | 15625000000 |
| 13 | 109375000000 |
| 14 | 781250000000 |
| 15 | 5468750000000 |
| 16 | 39062500000000 |
| 17 | 273437500000000 |
| 18 | 1953125000000000 |
| 19 | 13671875000000000 |
| 20 | 97656250000000000 |
| 21 | 683593750000000000 |
| 22 | 4882812500000000000 |
[1,7,50,350,2500,17500,125000,875000,6250000, 43750000,312500000,2187500000,15625000000, 109375000000,781250000000,5468750000000, 39062500000000,273437500000000,1953125000000000, 13671875000000000,97656250000000000, 683593750000000000,4882812500000000000] |