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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 19 |
| 6 | 80 |
| 7 | 395 |
| 8 | 2487 |
| 9 | 19890 |
| 10 | 206565 |
| 11 | 2804453 |
| 12 | 49872647 |
| 13 | 1158843214 |
| 14 | 35049606566 |
| 15 | 1374685228988 |
| 16 | 69690886873398 |
| 17 | 4554367168841547 |