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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 25 |
| 2 | 350 |
| 3 | 3575 |
| 4 | 29575 |
| 5 | 209381 |
| 6 | 1312075 |
| 7 | 7443825 |
| 8 | 38854075 |
| 9 | 188836375 |
| 10 | 862496902 |
| 11 | 3729343275 |
| 12 | 15356254650 |
| 13 | 60511763600 |
| 14 | 229125615600 |
| 15 | 836555203223 |
| 16 | 2953900713000 |
| 17 | 10113407774450 |
| 18 | 33649438734125 |
| 19 | 109017926343725 |
| 20 | 344525085375315 |
| 21 | 1063718962906450 |
[1,25,350,3575,29575,209381,1312075,7443825, 38854075,188836375,862496902,3729343275, 15356254650,60511763600,229125615600,836555203223, 2953900713000,10113407774450,33649438734125, 109017926343725,344525085375315,1063718962906450] |