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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 40 |
| 3 | 405 |
| 4 | 4875 |
| 5 | 67354 |
| 6 | 1044045 |
| 7 | 17867125 |
| 8 | 333554020 |
| 9 | 6730070329 |
| 10 | 145676361731 |
| 11 | 3362266525430 |
| 12 | 82326965117385 |
| 13 | 2129349953723509 |
| 14 | 57961263778376192 |
| 15 | 1655067729384150829 |
| 16 | 49437118345913831595 |
| 17 | 1540860755766376984434 |
| 18 | 50000885646431513577973 |
[1,5,40,405,4875,67354,1044045,17867125,333554020, 6730070329,145676361731,3362266525430, 82326965117385,2129349953723509,57961263778376192, 1655067729384150829,49437118345913831595, 1540860755766376984434,50000885646431513577973] |