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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 8 |
| 4 | 20 |
| 5 | 36 |
| 6 | 84 |
| 7 | 148 |
| 8 | 340 |
| 9 | 596 |
| 10 | 1364 |
| 11 | 2388 |
| 12 | 5460 |
| 13 | 9556 |
| 14 | 21844 |
| 15 | 38228 |
| 16 | 87380 |
| 17 | 152916 |
| 18 | 349524 |
| 19 | 611668 |
| 20 | 1398100 |
| 21 | 2446676 |
| 22 | 5592404 |
| 23 | 9786708 |
| 24 | 22369620 |
| 25 | 39146836 |
| 26 | 89478484 |
| 27 | 156587348 |
| 28 | 357913940 |
| 29 | 626349396 |
| 30 | 1431655764 |
| 31 | 2505397588 |
[1,4,8,20,36,84,148,340,596,1364,2388,5460,9556, 21844,38228,87380,152916,349524,611668,1398100, 2446676,5592404,9786708,22369620,39146836, 89478484,156587348,357913940,626349396,1431655764, 2505397588] |