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| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 52 |
| 3 | 132 |
| 4 | 340 |
| 5 | 868 |
| 6 | 2228 |
| 7 | 5700 |
| 8 | 14612 |
| 9 | 37412 |
| 10 | 95860 |
| 11 | 245508 |
| 12 | 628948 |
| 13 | 1610980 |
| 14 | 4126772 |
| 15 | 10570692 |
| 16 | 27077780 |
| 17 | 69360548 |
| 18 | 177671668 |
| 19 | 455113860 |
| 20 | 1165800532 |
| 21 | 2986255972 |
| 22 | 7649458100 |
| 23 | 19594481988 |
| 24 | 50192314388 |
| 25 | 128570242340 |
| 26 | 329339499892 |
[20,52,132,340,868,2228,5700,14612,37412,95860, 245508,628948,1610980,4126772,10570692,27077780, 69360548,177671668,455113860,1165800532, 2986255972,7649458100,19594481988,50192314388, 128570242340,329339499892] |