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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 41 |
| 4 | 309 |
| 5 | 2473 |
| 6 | 20609 |
| 7 | 1766488 |
| 8 | 15456771 |
| 9 | 137393521 |
| 10 | 12365416891 |
| 11 | 1124128808274 |
| 12 | 103045140758451 |
| 13 | 9511859146933940 |
| 14 | 883244063643865859 |
| 15 | 82436112606760813509 |
| 16 | 7728385556883826266471 |
| 17 | 727377464177301295667861 |
[1,6,41,309,2473,20609,1766488,15456771,137393521, 12365416891,1124128808274,103045140758451, 9511859146933940,883244063643865859, 82436112606760813509,7728385556883826266471, 727377464177301295667861] |