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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 15 |
| 3 | 100 |
| 4 | 868 |
| 5 | 7780 |
| 6 | 69988 |
| 7 | 629860 |
| 8 | 5668708 |
| 9 | 51018340 |
| 10 | 459165028 |
| 11 | 4132485220 |
| 12 | 37192366948 |
| 13 | 334731302500 |
| 14 | 3012581722468 |
| 15 | 27113235502180 |
| 16 | 244019119519588 |
| 17 | 2196172075676260 |
| 18 | 19765548681086308 |
| 19 | 177889938129776740 |
[2,15,100,868,7780,69988,629860,5668708,51018340, 459165028,4132485220,37192366948,334731302500, 3012581722468,27113235502180,244019119519588, 2196172075676260,19765548681086308, 177889938129776740] |