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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 77 |
| 2 | 1848 |
| 3 | 24024 |
| 4 | 210210 |
| 5 | 1387386 |
| 6 | 7399392 |
| 7 | 33372768 |
| 8 | 131405274 |
| 9 | 462351890 |
| 10 | 1479526048 |
| 11 | 4365213216 |
| 12 | 12004336344 |
| 13 | 31040798712 |
| 14 | 76018282560 |
| 15 | 177375992640 |
| 16 | 396324483555 |
| 17 | 851617661895 |
| 18 | 1766318113560 |
| 19 | 3547314771000 |
| 20 | 6917263803450 |
| 21 | 13128684361650 |
| 22 | 24304341297600 |
[1,77,1848,24024,210210,1387386,7399392,33372768, 131405274,462351890,1479526048,4365213216, 12004336344,31040798712,76018282560,177375992640, 396324483555,851617661895,1766318113560, 3547314771000,6917263803450,13128684361650, 24304341297600] |