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 | 2 |
| 1 | 15 |
| 2 | 171 |
| 3 | 2160 |
| 4 | 27783 |
| 5 | 358425 |
| 6 | 4626234 |
| 7 | 59716035 |
| 8 | 770832207 |
| 9 | 9950150160 |
| 10 | 128439782811 |
| 11 | 1657942687845 |
| 12 | 21401266181778 |
| 13 | 276254540154855 |
| 14 | 3565983915414819 |
| 15 | 46030886147041200 |
| 16 | 594181726489417887 |
| 17 | 7669891971371155905 |
| 18 | 99005472955353055626 |