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 | 3 |
| 2 | 9 |
| 3 | 29 |
| 4 | 103 |
| 5 | 405 |
| 6 | 1753 |
| 7 | 8279 |
| 8 | 42293 |
| 9 | 231949 |
| 10 | 1357139 |
| 11 | 8427193 |
| 12 | 55288873 |
| 13 | 381798643 |
| 14 | 2765917089 |
| 15 | 20960284293 |
| 16 | 165729739607 |
| 17 | 1364153612317 |
| 18 | 11665484410113 |
| 19 | 103448316470743 |
| 20 | 949739632313501 |
| 21 | 9013431476894645 |
| 22 | 88304011710168691 |