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 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 50 |
| 6 | 273 |
| 7 | 1687 |
| 8 | 11505 |
| 9 | 86004 |
| 10 | 700445 |
| 11 | 6163751 |
| 12 | 58148547 |
| 13 | 584622766 |
| 14 | 6235669629 |
| 15 | 70286727435 |
| 16 | 834288853217 |
| 17 | 10395375065096 |
| 18 | 135592878107673 |
| 19 | 1846897191981835 |
| 20 | 26212412703559515 |
| 21 | 386874121137659274 |
| 22 | 5927186655133112105 |
| 23 | 94108950154465139807 |