The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 28 |
| 2 | 784 |
| 3 | 4706 |
| 4 | 28681 |
| 5 | 222487 |
| 6 | 1474641 |
| 7 | 9072707 |
| 8 | 57903614 |
| 9 | 364876262 |
| 10 | 2242331814 |
| 11 | 13768713631 |
| 12 | 84428280229 |
| 13 | 514353352557 |
| 14 | 3124595619191 |
| 15 | 18960957925634 |
| 16 | 114849976141130 |
| 17 | 694688437603860 |
| 18 | 4198845405962339 |
| 19 | 25361823055909609 |
[28,784,4706,28681,222487,1474641,9072707, 57903614,364876262,2242331814,13768713631, 84428280229,514353352557,3124595619191, 18960957925634,114849976141130,694688437603860, 4198845405962339,25361823055909609] |