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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 2 |
| 3 | 4 |
| 4 | 5 |
| 5 | 8 |
| 6 | 11 |
| 7 | 40 |
| 8 | 59 |
| 9 | 169 |
| 10 | 555 |
| 11 | 1319 |
| 12 | 3615 |
| 13 | 20488 |
| 14 | 46826 |
| 15 | 218870 |
| 16 | 1193201 |
| 17 | 4783860 |
| 18 | 22240814 |
| 19 | 199704231 |
| 20 | 805091958 |
| 21 | 6227071279 |
| 22 | 56791304489 |
| 23 | 381075628434 |
| 24 | 2947943372020 |
| 25 | 45668975412143 |
| 26 | 300746133172408 |
[1,2,2,4,5,8,11,40,59,169,555,1319,3615,20488, 46826,218870,1193201,4783860,22240814,199704231, 805091958,6227071279,56791304489,381075628434, 2947943372020,45668975412143,300746133172408] |