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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 51 |
| 4 | 791 |
| 5 | 16711 |
| 6 | 449575 |
| 7 | 14738537 |
| 8 | 570860449 |
| 9 | 25534320961 |
| 10 | 1296145448621 |
| 11 | 73644069770107 |
| 12 | 4631766294581959 |
| 13 | 319523289664700279 |
| 14 | 23992478864877747151 |
| 15 | 1948216141720780468561 |
| 16 | 170121586262631029818433 |
| 17 | 15897659114382366967974145 |
| 18 | 1583109774987253349677203349 |
| 19 | 167363833662976153803805436291 |
| 20 | 18721216520653602533835176495671 |
[1,1,5,51,791,16711,449575,14738537,570860449, 25534320961,1296145448621,73644069770107, 4631766294581959,319523289664700279, 23992478864877747151,1948216141720780468561, 170121586262631029818433, 15897659114382366967974145, 1583109774987253349677203349, 167363833662976153803805436291, 18721216520653602533835176495671] |