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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 5 |
| 4 | 20 |
| 5 | 59 |
| 6 | 24 |
| 7 | 151 |
| 8 | 272 |
| 9 | 687 |
| 10 | 1760 |
| 11 | 1887 |
| 12 | 4416 |
| 13 | 11199 |
| 14 | 27008 |
| 15 | 29055 |
| 16 | 67840 |
| 17 | 185087 |
| 18 | 411136 |
| 19 | 304639 |
| 20 | 1082368 |
| 21 | 2976767 |
| 22 | 6797312 |
| 23 | 4839423 |
| 24 | 16838656 |
| 25 | 50147327 |
| 26 | 117858304 |
| 27 | 15261695 |
| 28 | 472236032 |
| 29 | 189710335 |
| 30 | 1293123584 |
| 31 | 2390851583 |
| 32 | 5745868800 |
| 33 | 16517890047 |
[1,2,6,5,20,59,24,151,272,687,1760,1887,4416, 11199,27008,29055,67840,185087,411136,304639, 1082368,2976767,6797312,4839423,16838656,50147327, 117858304,15261695,472236032,189710335,1293123584, 2390851583,5745868800,16517890047] |