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| n | a(n) |
|---|---|
| 0 | 18 |
| 1 | 73 |
| 2 | 2646 |
| 3 | 10657 |
| 4 | 386298 |
| 5 | 1555849 |
| 6 | 56396862 |
| 7 | 227143297 |
| 8 | 8233555554 |
| 9 | 33161365513 |
| 10 | 1202042714022 |
| 11 | 4841332221601 |
| 12 | 175490002691658 |
| 13 | 706801342988233 |
| 14 | 25620338350268046 |
| 15 | 103188154744060417 |
| 16 | 3740393909136443058 |
| 17 | 15064763791289832649 |
| 18 | 546071890395570418422 |
[18,73,2646,10657,386298,1555849,56396862, 227143297,8233555554,33161365513,1202042714022, 4841332221601,175490002691658,706801342988233, 25620338350268046,103188154744060417, 3740393909136443058,15064763791289832649, 546071890395570418422] |