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 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 52 |
| 4 | 425 |
| 5 | 4206 |
| 6 | 50737 |
| 7 | 708464 |
| 8 | 11350257 |
| 9 | 204171130 |
| 10 | 4084757561 |
| 11 | 89849981772 |
| 12 | 2156575777369 |
| 13 | 56068679418662 |
| 14 | 1569955094823585 |
| 15 | 47098171778191816 |
| 16 | 1507149193966389857 |
| 17 | 51242941744764975474 |