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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 16 |
| 5 | 43 |
| 6 | 117 |
| 7 | 318 |
| 8 | 865 |
| 9 | 2351 |
| 10 | 6391 |
| 11 | 17372 |
| 12 | 47222 |
| 13 | 128363 |
| 14 | 348927 |
| 15 | 948482 |
| 16 | 2578241 |
| 17 | 7008386 |
| 18 | 19050768 |
| 19 | 51785356 |
| 20 | 140767193 |
| 21 | 382644902 |
| 22 | 1040136684 |
| 23 | 2827384648 |
| 24 | 7685628310 |
| 25 | 20891703776 |
| 26 | 56789538739 |
| 27 | 154369971201 |
| 28 | 419621087576 |
| 29 | 1140648377196 |
| 30 | 3100603756393 |
[1,2,6,16,43,117,318,865,2351,6391,17372,47222, 128363,348927,948482,2578241,7008386,19050768, 51785356,140767193,382644902,1040136684, 2827384648,7685628310,20891703776,56789538739, 154369971201,419621087576,1140648377196, 3100603756393] |