The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 40 |
| 6 | 111 |
| 7 | 299 |
| 8 | 793 |
| 9 | 2096 |
| 10 | 5553 |
| 11 | 14758 |
| 12 | 39294 |
| 13 | 104673 |
| 14 | 278773 |
| 15 | 742197 |
| 16 | 1975582 |
| 17 | 5258269 |
| 18 | 13995810 |
| 19 | 37253664 |
| 20 | 99163215 |
| 21 | 263958623 |
| 22 | 702620141 |
| 23 | 1870267300 |
| 24 | 4978351449 |
| 25 | 13251558642 |
| 26 | 35273486910 |
| 27 | 93892303905 |
| 28 | 249926170873 |
| 29 | 665263248665 |
| 30 | 1770823721530 |
[0,1,2,5,14,40,111,299,793,2096,5553,14758,39294, 104673,278773,742197,1975582,5258269,13995810, 37253664,99163215,263958623,702620141,1870267300, 4978351449,13251558642,35273486910,93892303905, 249926170873,665263248665,1770823721530] |