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| n | a(n) |
|---|---|
| 2 | 2 |
| 3 | 8 |
| 4 | 34 |
| 5 | 160 |
| 6 | 806 |
| 7 | 4256 |
| 8 | 23256 |
| 9 | 130416 |
| 10 | 746350 |
| 11 | 4341480 |
| 12 | 25594530 |
| 13 | 152585472 |
| 14 | 918324904 |
| 15 | 5572034240 |
| 16 | 34048494608 |
| 17 | 209347674768 |
| 18 | 1294227005694 |
| 19 | 8040125464280 |
| 20 | 50165404177350 |
| 21 | 314229490307040 |
| 22 | 1975283452131990 |
| 23 | 12456968750889600 |
| 24 | 78790615438385760 |
| 25 | 499700263517332800 |
[2,8,34,160,806,4256,23256,130416,746350,4341480, 25594530,152585472,918324904,5572034240, 34048494608,209347674768,1294227005694, 8040125464280,50165404177350,314229490307040, 1975283452131990,12456968750889600, 78790615438385760,499700263517332800] |