The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 4 |
| 5 | 13 |
| 6 | 35 |
| 7 | 85 |
| 8 | 194 |
| 9 | 425 |
| 10 | 904 |
| 11 | 1885 |
| 12 | 3878 |
| 13 | 7904 |
| 14 | 16008 |
| 15 | 32282 |
| 16 | 64913 |
| 17 | 130280 |
| 18 | 261145 |
| 19 | 523036 |
| 20 | 1047017 |
| 21 | 2095222 |
| 22 | 4191927 |
| 23 | 8385695 |
| 24 | 16773663 |
| 25 | 33550117 |
| 26 | 67103645 |
| 27 | 134211440 |
| 28 | 268427907 |
| 29 | 536861880 |
| 30 | 1073731053 |
| 31 | 2147470842 |
| 32 | 4294952115 |
| 33 | 8589916646 |
| 34 | 17179848025 |
[0,0,1,4,13,35,85,194,425,904,1885,3878,7904, 16008,32282,64913,130280,261145,523036,1047017, 2095222,4191927,8385695,16773663,33550117, 67103645,134211440,268427907,536861880,1073731053, 2147470842,4294952115,8589916646,17179848025] |