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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 85 |
| 3 | 1300 |
| 4 | 17500 |
| 5 | 220000 |
| 6 | 2650000 |
| 7 | 31000000 |
| 8 | 355000000 |
| 9 | 4000000000 |
| 10 | 44500000000 |
| 11 | 490000000000 |
| 12 | 5350000000000 |
| 13 | 58000000000000 |
| 14 | 625000000000000 |
| 15 | 6700000000000000 |
| 16 | 71500000000000000 |
| 17 | 760000000000000000 |
| 18 | 8050000000000000000 |
| 19 | 85000000000000000000 |
| 20 | 895000000000000000000 |
[4,85,1300,17500,220000,2650000,31000000, 355000000,4000000000,44500000000,490000000000, 5350000000000,58000000000000,625000000000000, 6700000000000000,71500000000000000, 760000000000000000,8050000000000000000, 85000000000000000000,895000000000000000000] |