The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 11 |
| 5 | 26 |
| 6 | 65 |
| 7 | 163 |
| 8 | 416 |
| 9 | 1081 |
| 10 | 2837 |
| 11 | 7516 |
| 12 | 20089 |
| 13 | 54077 |
| 14 | 146478 |
| 15 | 398997 |
| 16 | 1092215 |
| 17 | 3003014 |
| 18 | 8289569 |
| 19 | 22964919 |
| 20 | 63828252 |
| 21 | 177931665 |
| 22 | 497367721 |
| 23 | 1393768952 |
| 24 | 3914793457 |
| 25 | 11019379609 |
| 26 | 31079140922 |
| 27 | 87818240869 |
| 28 | 248571086403 |
| 29 | 704722488690 |
[1,2,5,11,26,65,163,416,1081,2837,7516,20089, 54077,146478,398997,1092215,3003014,8289569, 22964919,63828252,177931665,497367721,1393768952, 3914793457,11019379609,31079140922,87818240869, 248571086403,704722488690] |