The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 25 |
| 4 | 57 |
| 5 | 185 |
| 6 | 441 |
| 7 | 4537 |
| 8 | 37305 |
| 9 | 102841 |
| 10 | 233913 |
| 11 | 758201 |
| 12 | 1806777 |
| 13 | 18583993 |
| 14 | 152801721 |
| 15 | 421237177 |
| 16 | 958108089 |
| 17 | 3105591737 |
| 18 | 7400559033 |
| 19 | 76120035769 |
| 20 | 625875849657 |
| 21 | 1725387477433 |
| 22 | 3924410732985 |
| 23 | 12720503755193 |
| 24 | 30312689799609 |
[1,9,25,57,185,441,4537,37305,102841,233913, 758201,1806777,18583993,152801721,421237177, 958108089,3105591737,7400559033,76120035769, 625875849657,1725387477433,3924410732985, 12720503755193,30312689799609] |