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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 18 |
| 3 | 0 |
| 4 | 631 |
| 5 | 0 |
| 6 | 23188 |
| 7 | 0 |
| 8 | 852298 |
| 9 | 0 |
| 10 | 31322020 |
| 11 | 0 |
| 12 | 1151041183 |
| 13 | 0 |
| 14 | 42298797564 |
| 15 | 0 |
| 16 | 1554405335830 |
| 17 | 0 |
| 18 | 57121595318958 |
| 19 | 0 |
| 20 | 2099115475346705 |
| 21 | 0 |
| 22 | 77138701114715724 |
| 23 | 0 |
| 24 | 2834707878337590102 |
| 25 | 0 |
| 26 | 104170392148337357776 |
| 27 | 0 |
| 28 | 3828073672066667898151 |
| 29 | 0 |
[0,18,0,631,0,23188,0,852298,0,31322020,0, 1151041183,0,42298797564,0,1554405335830,0, 57121595318958,0,2099115475346705,0, 77138701114715724,0,2834707878337590102,0, 104170392148337357776,0,3828073672066667898151,0] |