The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 42 |
| 4 | 171 |
| 5 | 751 |
| 6 | 3509 |
| 7 | 17135 |
| 8 | 86331 |
| 9 | 445161 |
| 10 | 2337097 |
| 11 | 12448148 |
| 12 | 67095277 |
| 13 | 365264609 |
| 14 | 2005444499 |
| 15 | 11091616038 |
| 16 | 61738014131 |
| 17 | 345581890401 |
| 18 | 1944078165249 |
| 19 | 10985238037766 |
| 20 | 62322123340849 |
| 21 | 354849796233957 |
| 22 | 2027085961125183 |
| 23 | 11614483110130587 |
| 24 | 66729581614802773 |
[1,3,11,42,171,751,3509,17135,86331,445161, 2337097,12448148,67095277,365264609,2005444499, 11091616038,61738014131,345581890401, 1944078165249,10985238037766,62322123340849, 354849796233957,2027085961125183, 11614483110130587,66729581614802773] |