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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 18 |
| 3 | 183 |
| 4 | 1927 |
| 5 | 20655 |
| 6 | 224498 |
| 7 | 2465815 |
| 8 | 27304863 |
| 9 | 304313548 |
| 10 | 3409370698 |
| 11 | 38362211823 |
| 12 | 433219457730 |
| 13 | 4907408334066 |
| 14 | 55737813431070 |
| 15 | 634528087334283 |
| 16 | 7238225267825429 |
| 17 | 82716464152842756 |
| 18 | 946771870186411896 |
| 19 | 10852263461880981957 |
[1,1,18,183,1927,20655,224498,2465815,27304863, 304313548,3409370698,38362211823,433219457730, 4907408334066,55737813431070,634528087334283, 7238225267825429,82716464152842756, 946771870186411896,10852263461880981957] |