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 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 11 |
| 6 | 88 |
| 7 | 638 |
| 8 | 4478 |
| 9 | 31199 |
| 10 | 218033 |
| 11 | 1535207 |
| 12 | 10910759 |
| 13 | 78310579 |
| 14 | 567588264 |
| 15 | 4152765025 |
| 16 | 30656248812 |
| 17 | 228215224472 |
| 18 | 1712296117750 |
| 19 | 12941799657414 |
| 20 | 98486737654025 |
| 21 | 754273093950128 |
| 22 | 5811161481943201 |
| 23 | 45020589539040033 |
| 24 | 350604675228411590 |
| 25 | 2743720335733822423 |