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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 16 |
| 5 | 43 |
| 6 | 120 |
| 7 | 369 |
| 8 | 1244 |
| 9 | 4449 |
| 10 | 16424 |
| 11 | 61645 |
| 12 | 233568 |
| 13 | 890421 |
| 14 | 3409866 |
| 15 | 13105083 |
| 16 | 50517580 |
| 17 | 195234557 |
| 18 | 756198408 |
| 19 | 2934687173 |
| 20 | 11408742152 |
| 21 | 44420399805 |
| 22 | 173191793402 |
| 23 | 676104404123 |
| 24 | 2642356839108 |
| 25 | 10337529692357 |
| 26 | 40481034411830 |
| 27 | 158658210122079 |
| 28 | 622329139387184 |
| 29 | 2442857958597649 |
[1,1,3,6,16,43,120,369,1244,4449,16424,61645, 233568,890421,3409866,13105083,50517580,195234557, 756198408,2934687173,11408742152,44420399805, 173191793402,676104404123,2642356839108, 10337529692357,40481034411830,158658210122079, 622329139387184,2442857958597649] |