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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 158 |
| 3 | 1939 |
| 4 | 15104 |
| 5 | 100306 |
| 6 | 618883 |
| 7 | 3589912 |
| 8 | 20094736 |
| 9 | 109292013 |
| 10 | 581664562 |
| 11 | 3041562335 |
| 12 | 15676720945 |
| 13 | 79831562595 |
| 14 | 402387057319 |
| 15 | 2010428875456 |
| 16 | 9967869656098 |
| 17 | 49089654019152 |
| 18 | 240315798975781 |
| 19 | 1170192251577228 |
[0,158,1939,15104,100306,618883,3589912,20094736, 109292013,581664562,3041562335,15676720945, 79831562595,402387057319,2010428875456, 9967869656098,49089654019152,240315798975781, 1170192251577228] |