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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 15 |
| 5 | 219 |
| 6 | 7839 |
| 7 | 777069 |
| 8 | 208836207 |
| 9 | 156458382975 |
| 10 | 328208016021561 |
| 11 | 1946879656265710431 |
| 12 | 32834193098697741359313 |
| 13 | 1582809785794578499063205301 |
| 14 | 218989607557709869788340418432175 |
| 15 | 87269441106898007902526099850864517077 |
[1,1,3,15,219,7839,777069,208836207,156458382975, 328208016021561,1946879656265710431, 32834193098697741359313, 1582809785794578499063205301, 218989607557709869788340418432175, 87269441106898007902526099850864517077] |