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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 32 |
| 5 | 112 |
| 6 | 430 |
| 7 | 1666 |
| 8 | 6695 |
| 9 | 27318 |
| 10 | 113765 |
| 11 | 479021 |
| 12 | 2044040 |
| 13 | 8799249 |
| 14 | 38215081 |
| 15 | 167159601 |
| 16 | 735913495 |
| 17 | 3258056505 |
| 18 | 14497203455 |
| 19 | 64796051816 |
| 20 | 290782505717 |
| 21 | 1309700100618 |
| 22 | 5918461474451 |
| 23 | 26826057282733 |
| 24 | 121927325532641 |
| 25 | 555576982877884 |
| 26 | 2537463320601835 |
| 27 | 11614220958892235 |
| 28 | 53265552869999108 |
[1,1,3,9,32,112,430,1666,6695,27318,113765,479021, 2044040,8799249,38215081,167159601,735913495, 3258056505,14497203455,64796051816,290782505717, 1309700100618,5918461474451,26826057282733, 121927325532641,555576982877884,2537463320601835, 11614220958892235,53265552869999108] |