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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 23 |
| 5 | 69 |
| 6 | 261 |
| 7 | 943 |
| 8 | 3815 |
| 9 | 15107 |
| 10 | 63219 |
| 11 | 262791 |
| 12 | 1130953 |
| 13 | 4838813 |
| 14 | 21185125 |
| 15 | 92593943 |
| 16 | 411160627 |
| 17 | 1823656199 |
| 18 | 8186105099 |
| 19 | 36728532951 |
| 20 | 166310761655 |