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| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 28 |
| 3 | 105 |
| 4 | 452 |
| 5 | 2401 |
| 6 | 11532 |
| 7 | 54613 |
| 8 | 268142 |
| 9 | 1322178 |
| 10 | 6448163 |
| 11 | 31571732 |
| 12 | 155259809 |
| 13 | 761566882 |
| 14 | 3736254465 |
| 15 | 18352493470 |
| 16 | 90106217668 |
| 17 | 442390202621 |
| 18 | 2172549312060 |
| 19 | 10668437072408 |
| 20 | 52387940298962 |
| 21 | 257266803546723 |
| 22 | 1263369837323884 |
[8,28,105,452,2401,11532,54613,268142,1322178, 6448163,31571732,155259809,761566882,3736254465, 18352493470,90106217668,442390202621, 2172549312060,10668437072408,52387940298962, 257266803546723,1263369837323884] |