The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 32 |
| 4 | 139 |
| 5 | 612 |
| 6 | 2780 |
| 7 | 12777 |
| 8 | 59474 |
| 9 | 279119 |
| 10 | 1319587 |
| 11 | 6272549 |
| 12 | 29957777 |
| 13 | 143629361 |
| 14 | 690899877 |
| 15 | 3332790064 |
| 16 | 16116297361 |
| 17 | 78099554494 |
| 18 | 379183671290 |
| 19 | 1844059563096 |
| 20 | 8981468647748 |
| 21 | 43802659925084 |
| 22 | 213883830813678 |
| 23 | 1045516504740462 |
| 24 | 5115841042217242 |
| 25 | 25055289097485312 |
| 26 | 122813356787701498 |
[1,2,8,32,139,612,2780,12777,59474,279119,1319587, 6272549,29957777,143629361,690899877,3332790064, 16116297361,78099554494,379183671290, 1844059563096,8981468647748,43802659925084, 213883830813678,1045516504740462,5115841042217242, 25055289097485312,122813356787701498] |