The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 3 |
| 3 | 7 |
| 4 | 16 |
| 5 | 37 |
| 6 | 89 |
| 7 | 216 |
| 8 | 529 |
| 9 | 1307 |
| 10 | 3248 |
| 11 | 8111 |
| 12 | 20339 |
| 13 | 51176 |
| 14 | 129143 |
| 15 | 326717 |
| 16 | 828374 |
| 17 | 2104361 |
| 18 | 5354979 |
| 19 | 13647682 |
| 20 | 34830191 |
| 21 | 89000157 |
| 22 | 227674188 |
| 23 | 583017657 |
| 24 | 1494365341 |
| 25 | 3833592212 |
| 26 | 9842373849 |
| 27 | 25287895051 |
| 28 | 65016153154 |
| 29 | 167264946727 |
[1,2,3,7,16,37,89,216,529,1307,3248,8111,20339, 51176,129143,326717,828374,2104361,5354979, 13647682,34830191,89000157,227674188,583017657, 1494365341,3833592212,9842373849,25287895051, 65016153154,167264946727] |