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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 24 |
| 4 | 93 |
| 5 | 376 |
| 6 | 1560 |
| 7 | 6606 |
| 8 | 28459 |
| 9 | 124092 |
| 10 | 546417 |
| 11 | 2424978 |
| 12 | 10834083 |
| 13 | 48674504 |
| 14 | 219721426 |
| 15 | 995917393 |
| 16 | 4530389392 |
| 17 | 20673892690 |
| 18 | 94608077696 |
| 19 | 434035171255 |
| 20 | 1995741367560 |
| 21 | 9195456939078 |
| 22 | 42447487636534 |
| 23 | 196277742105506 |
| 24 | 909013161586392 |
| 25 | 4215958362164549 |
| 26 | 19579546434216768 |
| 27 | 91043208191401018 |
[1,2,7,24,93,376,1560,6606,28459,124092,546417, 2424978,10834083,48674504,219721426,995917393, 4530389392,20673892690,94608077696,434035171255, 1995741367560,9195456939078,42447487636534, 196277742105506,909013161586392,4215958362164549, 19579546434216768,91043208191401018] |