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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 35 |
| 3 | 274 |
| 4 | 2261 |
| 5 | 19228 |
| 6 | 166726 |
| 7 | 1465399 |
| 8 | 13008995 |
| 9 | 116374621 |
| 10 | 1047384196 |
| 11 | 9473049468 |
| 12 | 86028257666 |
| 13 | 783933555215 |
| 14 | 7164492260569 |
| 15 | 65642607902166 |
| 16 | 602754037713365 |
| 17 | 5545405993706068 |
| 18 | 51105791195006851 |
| 19 | 471704973073493801 |
| 20 | 4359800639429095004 |
[1,5,35,274,2261,19228,166726,1465399,13008995, 116374621,1047384196,9473049468,86028257666, 783933555215,7164492260569,65642607902166, 602754037713365,5545405993706068, 51105791195006851,471704973073493801, 4359800639429095004] |