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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 23 |
| 5 | 102 |
| 6 | 497 |
| 7 | 2586 |
| 8 | 14127 |
| 9 | 80146 |
| 10 | 468688 |
| 11 | 2810163 |
| 12 | 17206549 |
| 13 | 107261051 |
| 14 | 679096359 |
| 15 | 4358360362 |
| 16 | 28309516828 |
| 17 | 185862601727 |
| 18 | 1232042778231 |
| 19 | 8238155634738 |
| 20 | 55521191613041 |
| 21 | 376888928783870 |
| 22 | 2575334987109807 |
| 23 | 17704834935517727 |
| 24 | 122401523831513816 |