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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 20 |
| 3 | 26 |
| 4 | 0 |
| 5 | 96 |
| 6 | 524 |
| 7 | 726 |
| 8 | 0 |
| 9 | 2760 |
| 10 | 15560 |
| 11 | 22084 |
| 12 | 0 |
| 13 | 85120 |
| 14 | 487564 |
| 15 | 700966 |
| 16 | 0 |
| 17 | 2723256 |
| 18 | 15746520 |
| 19 | 22820940 |
| 20 | 0 |
| 21 | 89115840 |
| 22 | 518517560 |
| 23 | 755594620 |
| 24 | 0 |
| 25 | 2961237136 |
| 26 | 17306539536 |
| 27 | 25319793096 |
| 28 | 0 |
| 29 | 99494853120 |
| 30 | 583417062540 |
| 31 | 856125569286 |
| 32 | 0 |
[4,20,26,0,96,524,726,0,2760,15560,22084,0,85120, 487564,700966,0,2723256,15746520,22820940,0, 89115840,518517560,755594620,0,2961237136, 17306539536,25319793096,0,99494853120, 583417062540,856125569286,0] |