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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 8 |
| 3 | 69 |
| 4 | 598 |
| 5 | 5229 |
| 6 | 46148 |
| 7 | 410564 |
| 8 | 3677205 |
| 9 | 33118004 |
| 10 | 299653447 |
| 11 | 2721863556 |
| 12 | 24805834384 |
| 13 | 226714986482 |
| 14 | 2077219038583 |
| 15 | 19073322225093 |
| 16 | 175469528064836 |
| 17 | 1617021669150125 |
| 18 | 14924185776171959 |
| 19 | 137930294999776878 |
| 20 | 1276338562136112694 |
| 21 | 11823881876462306463 |
[1,1,8,69,598,5229,46148,410564,3677205,33118004, 299653447,2721863556,24805834384,226714986482, 2077219038583,19073322225093,175469528064836, 1617021669150125,14924185776171959, 137930294999776878,1276338562136112694, 11823881876462306463] |