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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 25 |
| 4 | 121 |
| 5 | 583 |
| 6 | 2789 |
| 7 | 13287 |
| 8 | 63149 |
| 9 | 299697 |
| 10 | 1421107 |
| 11 | 6735253 |
| 12 | 31911985 |
| 13 | 151174893 |
| 14 | 716081551 |
| 15 | 3391722505 |
| 16 | 16064368343 |
| 17 | 76084921797 |
| 18 | 360353446761 |
| 19 | 1706695118265 |
| 20 | 8083167563465 |
| 21 | 38283027343193 |
| 22 | 181313615940197 |
| 23 | 858725280497117 |
| 24 | 4067034860337649 |
[0,1,5,25,121,583,2789,13287,63149,299697,1421107, 6735253,31911985,151174893,716081551,3391722505, 16064368343,76084921797,360353446761, 1706695118265,8083167563465,38283027343193, 181313615940197,858725280497117,4067034860337649] |