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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 42 |
| 4 | 161 |
| 5 | 616 |
| 6 | 2352 |
| 7 | 8967 |
| 8 | 34153 |
| 9 | 129997 |
| 10 | 494606 |
| 11 | 1881355 |
| 12 | 7154980 |
| 13 | 27208132 |
| 14 | 103456689 |
| 15 | 393367835 |
| 16 | 1495638123 |
| 17 | 5686513994 |
| 18 | 21620239081 |
| 19 | 82199944512 |
| 20 | 312521862408 |
| 21 | 1188195487255 |
| 22 | 4517461948657 |
| 23 | 17175149855885 |
| 24 | 65298950120782 |
| 25 | 248262786503683 |
[1,3,11,42,161,616,2352,8967,34153,129997,494606, 1881355,7154980,27208132,103456689,393367835, 1495638123,5686513994,21620239081,82199944512, 312521862408,1188195487255,4517461948657, 17175149855885,65298950120782,248262786503683] |