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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 12 |
| 3 | 26 |
| 4 | 56 |
| 5 | 120 |
| 6 | 258 |
| 7 | 554 |
| 8 | 1190 |
| 9 | 2556 |
| 10 | 5490 |
| 11 | 11792 |
| 12 | 25328 |
| 13 | 54402 |
| 14 | 116850 |
| 15 | 250982 |
| 16 | 539084 |
| 17 | 1157898 |
| 18 | 2487048 |
| 19 | 5341928 |
| 20 | 11473922 |
| 21 | 24644826 |
| 22 | 52934598 |
| 23 | 113698172 |
| 24 | 244212194 |
| 25 | 524543136 |
| 26 | 1126665696 |
| 27 | 2419964162 |
| 28 | 5197838690 |
| 29 | 11164432710 |
[6,12,26,56,120,258,554,1190,2556,5490,11792, 25328,54402,116850,250982,539084,1157898,2487048, 5341928,11473922,24644826,52934598,113698172, 244212194,524543136,1126665696,2419964162, 5197838690,11164432710] |