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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 19 |
| 3 | 118 |
| 4 | 695 |
| 5 | 4058 |
| 6 | 23659 |
| 7 | 137902 |
| 8 | 803759 |
| 9 | 4684658 |
| 10 | 27304195 |
| 11 | 159140518 |
| 12 | 927538919 |
| 13 | 5406093002 |
| 14 | 31509019099 |
| 15 | 183648021598 |
| 16 | 1070379110495 |
| 17 | 6238626641378 |
| 18 | 36361380737779 |
| 19 | 211929657785302 |
| 20 | 1235216565974039 |
[2,19,118,695,4058,23659,137902,803759,4684658, 27304195,159140518,927538919,5406093002, 31509019099,183648021598,1070379110495, 6238626641378,36361380737779,211929657785302, 1235216565974039] |