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| n | a(n) |
|---|---|
| 1 | 222 |
| 2 | 1180 |
| 3 | 5029 |
| 4 | 18859 |
| 5 | 65310 |
| 6 | 214812 |
| 7 | 682921 |
| 8 | 2122743 |
| 9 | 6501118 |
| 10 | 19720580 |
| 11 | 59462069 |
| 12 | 178644459 |
| 13 | 535616774 |
| 14 | 1604254580 |
| 15 | 4803055177 |
| 16 | 14379531399 |
| 17 | 43056528118 |
| 18 | 128955131820 |
| 19 | 386326404261 |
| 20 | 1157662173067 |
| 21 | 3469836562702 |
[222,1180,5029,18859,65310,214812,682921,2122743, 6501118,19720580,59462069,178644459,535616774, 1604254580,4803055177,14379531399,43056528118, 128955131820,386326404261,1157662173067, 3469836562702] |