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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 9 |
| 4 | 114 |
| 5 | 1332 |
| 6 | 25404 |
| 7 | 395460 |
| 8 | 9724901 |
| 9 | 207584371 |
| 10 | 6120938951 |
| 11 | 151737244257 |
| 12 | 5932533980409 |
| 13 | 168400694345669 |
| 14 | 7145593797561899 |
| 15 | 260681076993636793 |
| 16 | 12410128414690753548 |
| 17 | 473029927456547840472 |
| 18 | 27572016889372245275679 |