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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 26 |
| 5 | 89 |
| 6 | 318 |
| 7 | 1179 |
| 8 | 4496 |
| 9 | 17509 |
| 10 | 69447 |
| 11 | 279660 |
| 12 | 1140251 |
| 13 | 4700604 |
| 14 | 19562165 |
| 15 | 82080374 |
| 16 | 346945287 |
| 17 | 1476050901 |
| 18 | 6316320356 |
| 19 | 27171754157 |
| 20 | 117444283946 |
| 21 | 509831752711 |
| 22 | 2222006377759 |
| 23 | 9719412733619 |
| 24 | 42657093656488 |
| 25 | 187797041910083 |
| 26 | 829150188199854 |
| 27 | 3670621883050424 |
| 28 | 16290292060305337 |
[1,1,3,8,26,89,318,1179,4496,17509,69447,279660, 1140251,4700604,19562165,82080374,346945287, 1476050901,6316320356,27171754157,117444283946, 509831752711,2222006377759,9719412733619, 42657093656488,187797041910083,829150188199854, 3670621883050424,16290292060305337] |