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 | 5 |
| 2 | 17 |
| 3 | 53 |
| 4 | 3077 |
| 5 | 83501 |
| 6 | 425645 |
| 7 | 2270045 |
| 8 | 2717873 |
| 9 | 9038141 |
| 10 | 35452673 |
| 11 | 197759717 |
| 12 | 523608245 |
| 13 | 827370449 |
| 14 | 5734125917 |
| 15 | 46548912269 |
| 16 | 117539270981 |
| 17 | 207572633873 |
| 18 | 286185056525 |
| 19 | 439600764977 |
| 20 | 804164538869 |
| 21 | 1599998981789 |
| 22 | 20114203639877 |
| 23 | 102098975067917 |