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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 27 |
| 4 | 169 |
| 5 | 1138 |
| 6 | 8061 |
| 7 | 59188 |
| 8 | 446455 |
| 9 | 3438863 |
| 10 | 26935372 |
| 11 | 213883631 |
| 12 | 1717852129 |
| 13 | 13931065117 |
| 14 | 113913095218 |
| 15 | 938154381748 |
| 16 | 7774936633411 |
| 17 | 64791892224825 |
| 18 | 542598513709481 |
| 19 | 4564001359135661 |
| 20 | 38541714429405304 |
| 21 | 326640923339410701 |
[1,1,5,27,169,1138,8061,59188,446455,3438863, 26935372,213883631,1717852129,13931065117, 113913095218,938154381748,7774936633411, 64791892224825,542598513709481,4564001359135661, 38541714429405304,326640923339410701] |