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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 8 |
| 5 | 18 |
| 6 | 45 |
| 7 | 102 |
| 8 | 245 |
| 9 | 565 |
| 10 | 1324 |
| 11 | 3049 |
| 12 | 7066 |
| 13 | 16199 |
| 14 | 37187 |
| 15 | 84887 |
| 16 | 193532 |
| 17 | 439600 |
| 18 | 996818 |
| 19 | 2253941 |
| 20 | 5086980 |
| 21 | 11454778 |
| 22 | 25746467 |
| 23 | 57756522 |
| 24 | 129342179 |
| 25 | 289153474 |
| 26 | 645399011 |
| 27 | 1438308839 |
| 28 | 3200671082 |
| 29 | 7112360474 |
| 30 | 15783402471 |
| 31 | 34980122720 |
| 32 | 77428353682 |
[1,0,1,3,8,18,45,102,245,565,1324,3049,7066,16199, 37187,84887,193532,439600,996818,2253941,5086980, 11454778,25746467,57756522,129342179,289153474, 645399011,1438308839,3200671082,7112360474, 15783402471,34980122720,77428353682] |