This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 9 |
| 3 | 81 |
| 4 | 835 |
| 5 | 9990 |
| 6 | 137466 |
| 7 | 2148139 |
| 8 | 37662381 |
| 9 | 733015845 |
| 10 | 15693217705 |
| 11 | 366695853876 |
| 12 | 9289111077324 |
| 13 | 253623142901401 |
| 14 | 7425873460633005 |
| 15 | 232122372003909045 |
| 16 | 7715943399320562331 |
| 17 | 271796943164015920914 |
| 18 | 10114041937573463433966 |