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| n | a(n) |
|---|---|
| 1 | 641 |
| 2 | 1819 |
| 3 | 6157 |
| 4 | 12620 |
| 5 | 23680 |
| 6 | 74850 |
| 7 | 197804 |
| 8 | 383548 |
| 9 | 942638 |
| 10 | 2727852 |
| 11 | 6128454 |
| 12 | 13250442 |
| 13 | 35951522 |
| 14 | 91093240 |
| 15 | 199168800 |
| 16 | 485362526 |
| 17 | 1276770070 |
| 18 | 2989412528 |
| 19 | 6882229004 |
| 20 | 17541213370 |
| 21 | 43445183724 |
| 22 | 100482691170 |
| 23 | 244053647200 |
[641,1819,6157,12620,23680,74850,197804,383548, 942638,2727852,6128454,13250442,35951522,91093240, 199168800,485362526,1276770070,2989412528, 6882229004,17541213370,43445183724,100482691170, 244053647200] |