The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 36 |
| 4 | 171 |
| 5 | 758 |
| 6 | 3703 |
| 7 | 17223 |
| 8 | 85031 |
| 9 | 404527 |
| 10 | 2007916 |
| 11 | 9683182 |
| 12 | 48201412 |
| 13 | 234472255 |
| 14 | 1169082780 |
| 15 | 5720655827 |
| 16 | 28551336136 |
| 17 | 140301234515 |
| 18 | 700660163609 |
| 19 | 3453823563591 |
| 20 | 17255035881950 |
| 21 | 85259397084348 |
| 22 | 426058434614498 |
| 23 | 2109118652429128 |
| 24 | 10541493216537377 |
| 25 | 52260534623896583 |
| 26 | 261231343795450687 |
[1,2,9,36,171,758,3703,17223,85031,404527,2007916, 9683182,48201412,234472255,1169082780,5720655827, 28551336136,140301234515,700660163609, 3453823563591,17255035881950,85259397084348, 426058434614498,2109118652429128, 10541493216537377,52260534623896583, 261231343795450687] |