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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 10 |
| 2 | 87 |
| 3 | 708 |
| 4 | 5565 |
| 5 | 42798 |
| 6 | 324275 |
| 7 | 2430536 |
| 8 | 18068409 |
| 9 | 133454610 |
| 10 | 980588367 |
| 11 | 7174290060 |
| 12 | 52301288949 |
| 13 | 380120468406 |
| 14 | 2755437681195 |
| 15 | 19928252747664 |
| 16 | 143839643441265 |
| 17 | 1036380251867418 |
| 18 | 7455465737930567 |
| 19 | 53557027924956500 |
| 20 | 384241833300244269 |
| 21 | 2753539115904779070 |
[1,10,87,708,5565,42798,324275,2430536,18068409, 133454610,980588367,7174290060,52301288949, 380120468406,2755437681195,19928252747664, 143839643441265,1036380251867418,7455465737930567, 53557027924956500,384241833300244269, 2753539115904779070] |