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 | 4 |
| 3 | 13 |
| 4 | 60 |
| 5 | 291 |
| 6 | 1564 |
| 7 | 8671 |
| 8 | 49852 |
| 9 | 292927 |
| 10 | 1753964 |
| 11 | 10656757 |
| 12 | 65549844 |
| 13 | 407347747 |
| 14 | 2553684852 |
| 15 | 16130539053 |
| 16 | 102563204892 |
| 17 | 655918173287 |
| 18 | 4216358457772 |
| 19 | 27227967629683 |
| 20 | 176554882805940 |
| 21 | 1149099219084877 |
| 22 | 7504110622072860 |
| 23 | 49155856119036993 |
| 24 | 322903351882566436 |