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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 15 |
| 3 | 113 |
| 4 | 837 |
| 5 | 6183 |
| 6 | 45691 |
| 7 | 337607 |
| 8 | 2494595 |
| 9 | 18432707 |
| 10 | 136200301 |
| 11 | 1006391657 |
| 12 | 7436284415 |
| 13 | 54947122715 |
| 14 | 406007372211 |
| 15 | 3000011249847 |
| 16 | 22167251422541 |
| 17 | 163795064320249 |
| 18 | 1210290918990281 |
| 19 | 8942907496445513 |
| 20 | 66079645178783351 |
[1,15,113,837,6183,45691,337607,2494595,18432707, 136200301,1006391657,7436284415,54947122715, 406007372211,3000011249847,22167251422541, 163795064320249,1210290918990281,8942907496445513, 66079645178783351] |