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 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 55 |
| 6 | 206 |
| 7 | 781 |
| 8 | 3099 |
| 9 | 12421 |
| 10 | 50725 |
| 11 | 208870 |
| 12 | 868238 |
| 13 | 3631673 |
| 14 | 15281827 |
| 15 | 64610493 |
| 16 | 274346429 |
| 17 | 1169219224 |
| 18 | 4999544053 |
| 19 | 21440702381 |
| 20 | 92192889106 |