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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 29 |
| 5 | 256 |
| 6 | 3007 |
| 7 | 42932 |
| 8 | 721121 |
| 9 | 13982563 |
| 10 | 306967231 |
| 11 | 7527903208 |
| 12 | 203977383469 |
| 13 | 6051630040496 |
| 14 | 195111205542541 |
| 15 | 6792697846367791 |
| 16 | 253966747582533681 |
| 17 | 10149075292428481965 |
| 18 | 431705938073882999275 |
| 19 | 19474660918369182445456 |
| 20 | 928660364396786865580881 |
[1,1,4,29,256,3007,42932,721121,13982563, 306967231,7527903208,203977383469,6051630040496, 195111205542541,6792697846367791, 253966747582533681,10149075292428481965, 431705938073882999275,19474660918369182445456, 928660364396786865580881] |