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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 3 |
| 6 | 2 |
| 7 | 11 |
| 8 | 9 |
| 9 | 55 |
| 10 | 70 |
| 11 | 345 |
| 12 | 494 |
| 13 | 2412 |
| 14 | 3788 |
| 15 | 18127 |
| 16 | 30799 |
| 17 | 143255 |
| 18 | 256353 |
| 19 | 1173770 |
| 20 | 2190163 |
| 21 | 9892302 |
| 22 | 19130814 |
| 23 | 85289390 |
| 24 | 169923748 |
| 25 | 749329719 |
| 26 | 1531701274 |
| 27 | 6688893605 |
| 28 | 13984116304 |
| 29 | 60526543480 |
| 30 | 129073842978 |
[1,0,1,1,3,2,11,9,55,70,345,494,2412,3788,18127, 30799,143255,256353,1173770,2190163,9892302, 19130814,85289390,169923748,749329719,1531701274, 6688893605,13984116304,60526543480,129073842978] |