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 | 4 |
| 3 | 18 |
| 4 | 128 |
| 5 | 1404 |
| 6 | 18261 |
| 7 | 310346 |
| 8 | 5896727 |
| 9 | 135624239 |
| 10 | 3933101823 |
| 11 | 121926157640 |
| 12 | 4511267827531 |
| 13 | 184961980943492 |
| 14 | 7953365180610400 |
| 15 | 373808163488684049 |
| 16 | 19811832664899731265 |
| 17 | 1168898127229083969892 |