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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 19 |
| 5 | 101 |
| 6 | 676 |
| 7 | 5377 |
| 8 | 49295 |
| 9 | 510729 |
| 10 | 5894110 |
| 11 | 74915741 |
| 12 | 1039180187 |
| 13 | 15613569325 |
| 14 | 252501251744 |
| 15 | 4371586879129 |
| 16 | 80652138666871 |
| 17 | 1579212732426257 |
| 18 | 32701859350855770 |
| 19 | 713914404925713589 |
| 20 | 16384896394304282723 |
| 21 | 394340620941231415541 |
| 22 | 9929838681717090607612 |
[1,1,2,5,19,101,676,5377,49295,510729,5894110, 74915741,1039180187,15613569325,252501251744, 4371586879129,80652138666871,1579212732426257, 32701859350855770,713914404925713589, 16384896394304282723,394340620941231415541, 9929838681717090607612] |