The OEIS is supported by the many generous donors to the OEIS Foundation.
A215448 as a simple table
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 43 |
| 6 | 124 |
| 7 | 357 |
| 8 | 1028 |
| 9 | 2960 |
| 10 | 8523 |
| 11 | 24541 |
| 12 | 70663 |
| 13 | 203466 |
| 14 | 585857 |
| 15 | 1686908 |
| 16 | 4857258 |
| 17 | 13985917 |
| 18 | 40270843 |
| 19 | 115955271 |
| 20 | 333879896 |
| 21 | 961368845 |
| 22 | 2768151264 |
| 23 | 7970573896 |
| 24 | 22950352843 |
| 25 | 66082907265 |
| 26 | 190278147899 |
| 27 | 547884090854 |
| 28 | 1577569365297 |
| 29 | 4542429947992 |
[1,0,2,5,15,43,124,357,1028,2960,8523,24541,70663, 203466,585857,1686908,4857258,13985917,40270843, 115955271,333879896,961368845,2768151264, 7970573896,22950352843,66082907265,190278147899, 547884090854,1577569365297,4542429947992] |