The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 14 |
| 3 | 44 |
| 4 | 182 |
| 5 | 548 |
| 6 | 1932 |
| 7 | 5632 |
| 8 | 17654 |
| 9 | 49872 |
| 10 | 145020 |
| 11 | 395256 |
| 12 | 1090044 |
| 13 | 2876424 |
| 14 | 7606024 |
| 15 | 19503312 |
| 16 | 49850790 |
| 17 | 124543772 |
| 18 | 309436980 |
| 19 | 755268832 |
| 20 | 1831194724 |
| 21 | 4376807896 |
| 22 | 10387118328 |
| 23 | 24359228520 |
| 24 | 56720659372 |
| 25 | 130737105940 |
| 26 | 299256890672 |
| 27 | 678941040784 |
[1,2,14,44,182,548,1932,5632,17654,49872,145020, 395256,1090044,2876424,7606024,19503312,49850790, 124543772,309436980,755268832,1831194724, 4376807896,10387118328,24359228520,56720659372, 130737105940,299256890672,678941040784] |