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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 72 |
| 3 | 664 |
| 4 | 6184 |
| 5 | 57888 |
| 6 | 543544 |
| 7 | 5113872 |
| 8 | 48180456 |
| 9 | 454396000 |
| 10 | 4288773152 |
| 11 | 40503496536 |
| 12 | 382701222296 |
| 13 | 3617396099936 |
| 14 | 34203591636048 |
| 15 | 323492394385824 |
| 16 | 3060238763412072 |
| 17 | 28955508198895584 |
| 18 | 274018698082833760 |
| 19 | 2593539713410178528 |
| 20 | 24550565251665845664 |
[1,8,72,664,6184,57888,543544,5113872,48180456, 454396000,4288773152,40503496536,382701222296, 3617396099936,34203591636048,323492394385824, 3060238763412072,28955508198895584, 274018698082833760,2593539713410178528, 24550565251665845664] |