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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 1 |
| 8 | 6 |
| 9 | 16 |
| 10 | 31 |
| 11 | 56 |
| 12 | 102 |
| 13 | 179 |
| 14 | 426 |
| 15 | 1490 |
| 16 | 5164 |
| 17 | 18715 |
| 18 | 73281 |
| 19 | 253183 |
| 20 | 741420 |
| 21 | 1915072 |
| 22 | 4599352 |
| 23 | 10845192 |
| 24 | 26990806 |
| 25 | 76446936 |
| 26 | 251549461 |
| 27 | 918616924 |
| 28 | 3497341145 |
| 29 | 13161267180 |
| 30 | 47114251055 |
| 31 | 157204766841 |
| 32 | 487208649994 |
| 33 | 1416324380706 |
| 34 | 3944267803650 |
[1,0,0,0,0,0,1,1,6,16,31,56,102,179,426,1490,5164, 18715,73281,253183,741420,1915072,4599352, 10845192,26990806,76446936,251549461,918616924, 3497341145,13161267180,47114251055,157204766841, 487208649994,1416324380706,3944267803650] |