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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 4 |
| 3 | 14 |
| 4 | 46 |
| 5 | 154 |
| 6 | 578 |
| 7 | 2168 |
| 8 | 8182 |
| 9 | 31532 |
| 10 | 125070 |
| 11 | 493576 |
| 12 | 1967344 |
| 13 | 7989243 |
| 14 | 32449575 |
| 15 | 132284139 |
| 16 | 544422926 |
| 17 | 2252015827 |
| 18 | 9319866551 |
| 19 | 38789146879 |
| 20 | 162226732758 |
| 21 | 679162610573 |
| 22 | 2851506701472 |
| 23 | 12018168463717 |
| 24 | 50743114587121 |
| 25 | 214563325115979 |
| 26 | 909819286375420 |
| 27 | 3865266727785403 |
[1,2,4,14,46,154,578,2168,8182,31532,125070, 493576,1967344,7989243,32449575,132284139, 544422926,2252015827,9319866551,38789146879, 162226732758,679162610573,2851506701472, 12018168463717,50743114587121,214563325115979, 909819286375420,3865266727785403] |