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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 12 |
| 3 | 127 |
| 4 | 1222 |
| 5 | 11096 |
| 6 | 97140 |
| 7 | 830152 |
| 8 | 6977918 |
| 9 | 57968938 |
| 10 | 477479647 |
| 11 | 3908025133 |
| 12 | 31832823274 |
| 13 | 258341395508 |
| 14 | 2090604162540 |
| 15 | 16880171617952 |
| 16 | 136054564607870 |
| 17 | 1095059149237006 |
| 18 | 8803843758642693 |
| 19 | 70715260139217139 |
| 20 | 567591311612071157 |
| 21 | 4553028235287085366 |
[1,12,127,1222,11096,97140,830152,6977918, 57968938,477479647,3908025133,31832823274, 258341395508,2090604162540,16880171617952, 136054564607870,1095059149237006,8803843758642693, 70715260139217139,567591311612071157, 4553028235287085366] |