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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 5 |
| 3 | 34 |
| 4 | 255 |
| 5 | 2040 |
| 6 | 17000 |
| 7 | 145715 |
| 8 | 1275007 |
| 9 | 11333396 |
| 10 | 102000564 |
| 11 | 927277855 |
| 12 | 85000470043 |
| 13 | 784619723474 |
| 14 | 7285754575116 |
| 15 | 68000376034416 |
| 16 | 637503525322650 |
| 17 | 60000331795072942 |
| 18 | 566669800286800008 |
| 19 | 5368450739559157971 |
| 20 | 510002820258120007246 |
[1,5,34,255,2040,17000,145715,1275007,11333396, 102000564,927277855,85000470043,784619723474, 7285754575116,68000376034416,637503525322650, 60000331795072942,566669800286800008, 5368450739559157971,510002820258120007246] |