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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 27 |
| 3 | 130 |
| 4 | 855 |
| 5 | 5934 |
| 6 | 44487 |
| 7 | 341802 |
| 8 | 2691675 |
| 9 | 21524542 |
| 10 | 174348099 |
| 11 | 1426419858 |
| 12 | 11767964475 |
| 13 | 97764131646 |
| 14 | 817028814447 |
| 15 | 6863038218842 |
| 16 | 57906884938095 |
| 17 | 490505347906086 |
| 18 | 4169295457231347 |
| 19 | 35548729443032994 |
| 20 | 303941636737938639 |
[6,27,130,855,5934,44487,341802,2691675,21524542, 174348099,1426419858,11767964475,97764131646, 817028814447,6863038218842,57906884938095, 490505347906086,4169295457231347, 35548729443032994,303941636737938639] |