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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 4 |
| 3 | 10 |
| 4 | 16 |
| 5 | 210 |
| 6 | 52 |
| 7 | 10764 |
| 8 | 160 |
| 9 | 840 |
| 10 | 484 |
| 11 | 78225840 |
| 12 | 1456 |
| 13 | 5729631692400 |
| 14 | 4372 |
| 15 | 932723933480442148565520 |
| 16 | 13120 |
| 17 | 202096081896183783466278120 |
| 18 | 39364 |
| 19 | 1505075187143521116689096930825555405884185492185368021027531191578186233461600 |
[2,4,10,16,210,52,10764,160,840,484,78225840,1456, 5729631692400,4372,932723933480442148565520,13120, 202096081896183783466278120,39364, 15050751871435211166890969308255554058841854921853\ 68021027531191578186233461600] |