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| n | a(n) |
|---|---|
| 0 | 48 |
| 1 | 175 |
| 2 | 1680 |
| 3 | 25410 |
| 4 | 294000 |
| 5 | 2295513 |
| 6 | 12991440 |
| 7 | 57550100 |
| 8 | 211281840 |
| 9 | 669529875 |
| 10 | 1885734928 |
| 11 | 4823347830 |
| 12 | 11387316720 |
| 13 | 25126129245 |
| 14 | 52326450000 |
| 15 | 103659864168 |
| 16 | 196585724720 |
| 17 | 358766207415 |
| 18 | 632810010000 |
| 19 | 1082730294250 |
| 20 | 1802581066608 |
| 21 | 2927824829985 |
| 22 | 4650083620560 |
[48,175,1680,25410,294000,2295513,12991440, 57550100,211281840,669529875,1885734928, 4823347830,11387316720,25126129245,52326450000, 103659864168,196585724720,358766207415, 632810010000,1082730294250,1802581066608, 2927824829985,4650083620560] |