The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 9 |
| 3 | 28 |
| 4 | 121 |
| 5 | 496 |
| 6 | 2100 |
| 7 | 9017 |
| 8 | 38969 |
| 9 | 169975 |
| 10 | 744984 |
| 11 | 3282005 |
| 12 | 14513236 |
| 13 | 64394500 |
| 14 | 286519305 |
| 15 | 1277975053 |
| 16 | 5712392313 |
| 17 | 25581765122 |
| 18 | 114754116351 |
| 19 | 515530099946 |
| 20 | 2319115721576 |
| 21 | 10445215621547 |
| 22 | 47096725844837 |
| 23 | 212569226371737 |
| 24 | 960306310551860 |
| 25 | 4341968468524371 |
[1,9,28,121,496,2100,9017,38969,169975,744984, 3282005,14513236,64394500,286519305,1277975053, 5712392313,25581765122,114754116351,515530099946, 2319115721576,10445215621547,47096725844837, 212569226371737,960306310551860,4341968468524371] |