The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 28 |
| 5 | 84 |
| 6 | 272 |
| 7 | 911 |
| 8 | 3885 |
| 9 | 14049 |
| 10 | 50891 |
| 11 | 185464 |
| 12 | 735146 |
| 13 | 2794719 |
| 14 | 10565837 |
| 15 | 39940553 |
| 16 | 155711860 |
| 17 | 601589056 |
| 18 | 2317413464 |
| 19 | 8920255482 |
| 20 | 34742183340 |
| 21 | 135196049411 |
| 22 | 525683426601 |
| 23 | 2043377119966 |
| 24 | 7980296279061 |
[1,1,2,5,28,84,272,911,3885,14049,50891,185464, 735146,2794719,10565837,39940553,155711860, 601589056,2317413464,8920255482,34742183340, 135196049411,525683426601,2043377119966, 7980296279061] |