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 | 10 |
| 2 | 70 |
| 3 | 430 |
| 4 | 2990 |
| 5 | 21210 |
| 6 | 152752 |
| 7 | 1107368 |
| 8 | 8054662 |
| 9 | 58680898 |
| 10 | 427841510 |
| 11 | 3120550894 |
| 12 | 22764484280 |
| 13 | 166081792328 |
| 14 | 1211725839660 |
| 15 | 8840879076060 |
| 16 | 64504607657222 |
| 17 | 470639150157006 |
| 18 | 3433889688841786 |
| 19 | 25054462942728214 |