| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 8 |
| 2 | 74 |
| 3 | 736 |
| 4 | 7606 |
| 5 | 80464 |
| 6 | 864772 |
| 7 | 9400192 |
| 8 | 103061158 |
| 9 | 1137528688 |
| 10 | 12623082284 |
| 11 | 140697113792 |
| 12 | 1574005263676 |
| 13 | 17663830073504 |
| 14 | 198760191043784 |
| 15 | 2241743315230208 |
| 16 | 25335473017856774 |
| 17 | 286850379192127664 |
| 18 | 3252960763923781276 |
| 19 | 36942512756224955456 |
| 20 | 420084161646913792724 |
[1,8,74,736,7606,80464,864772,9400192,103061158, 1137528688,12623082284,140697113792,1574005263676, 17663830073504,198760191043784,2241743315230208, 25335473017856774,286850379192127664, 3252960763923781276,36942512756224955456, 420084161646913792724] |