The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 11 |
| 5 | 26 |
| 6 | 61 |
| 7 | 143 |
| 8 | 336 |
| 9 | 789 |
| 10 | 1853 |
| 11 | 4352 |
| 12 | 10221 |
| 13 | 24005 |
| 14 | 56378 |
| 15 | 132409 |
| 16 | 310975 |
| 17 | 730354 |
| 18 | 1715305 |
| 19 | 4028555 |
| 20 | 9461440 |
| 21 | 22221081 |
| 22 | 52188297 |
| 23 | 122569120 |
| 24 | 287865097 |
| 25 | 676078233 |
| 26 | 1587833266 |
| 27 | 3729175645 |
| 28 | 8758319459 |
| 29 | 20569736330 |
[1,1,2,5,11,26,61,143,336,789,1853,4352,10221, 24005,56378,132409,310975,730354,1715305,4028555, 9461440,22221081,52188297,122569120,287865097, 676078233,1587833266,3729175645,8758319459, 20569736330] |