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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 35 |
| 3 | 287 |
| 4 | 2501 |
| 5 | 22265 |
| 6 | 199655 |
| 7 | 1794707 |
| 8 | 16145801 |
| 9 | 145292525 |
| 10 | 1307573675 |
| 11 | 11767985927 |
| 12 | 105911341901 |
| 13 | 953200482785 |
| 14 | 8578799562095 |
| 15 | 77209181709947 |
| 16 | 694882592342801 |
| 17 | 6253943201945045 |
| 18 | 56285488430084915 |
| 19 | 506569394708502767 |
| 20 | 4559124548889740501 |
[1,5,35,287,2501,22265,199655,1794707,16145801, 145292525,1307573675,11767985927,105911341901, 953200482785,8578799562095,77209181709947, 694882592342801,6253943201945045, 56285488430084915,506569394708502767, 4559124548889740501] |