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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 13 |
| 6 | 65 |
| 7 | 387 |
| 8 | 2709 |
| 9 | 21673 |
| 10 | 195057 |
| 11 | 1950547 |
| 12 | 21456017 |
| 13 | 257472123 |
| 14 | 3347137599 |
| 15 | 46859925639 |
| 16 | 702898884585 |
| 17 | 11246382147523 |
| 18 | 191188496507891 |
| 19 | 3441392937086571 |
| 20 | 65386465804644849 |
| 21 | 1307729316092328701 |
| 22 | 27462315637938902721 |
| 23 | 604170944034649445339 |
| 24 | 13895931712796937242797 |
[1,1,1,3,13,65,387,2709,21673,195057,1950547, 21456017,257472123,3347137599,46859925639, 702898884585,11246382147523,191188496507891, 3441392937086571,65386465804644849, 1307729316092328701,27462315637938902721, 604170944034649445339,13895931712796937242797] |