The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 11 |
| 6 | 29 |
| 7 | 83 |
| 8 | 251 |
| 9 | 767 |
| 10 | 2403 |
| 11 | 7652 |
| 12 | 24758 |
| 13 | 80875 |
| 14 | 266803 |
| 15 | 887330 |
| 16 | 2972108 |
| 17 | 10016981 |
| 18 | 33942461 |
| 19 | 115572864 |
| 20 | 395226810 |
| 21 | 1356840007 |
| 22 | 4674552089 |
| 23 | 16156355357 |
| 24 | 56003840659 |
| 25 | 194651585875 |
| 26 | 678220460687 |
| 27 | 2368505647624 |
| 28 | 8288873657180 |
| 29 | 29064904732911 |
[1,1,2,4,11,29,83,251,767,2403,7652,24758,80875, 266803,887330,2972108,10016981,33942461,115572864, 395226810,1356840007,4674552089,16156355357, 56003840659,194651585875,678220460687, 2368505647624,8288873657180,29064904732911] |