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 | 4 |
| 2 | 16 |
| 3 | 62 |
| 4 | 237 |
| 5 | 901 |
| 6 | 3418 |
| 7 | 12956 |
| 8 | 49096 |
| 9 | 186029 |
| 10 | 704861 |
| 11 | 2670692 |
| 12 | 10119152 |
| 13 | 38341126 |
| 14 | 145273353 |
| 15 | 550436561 |
| 16 | 2085588866 |
| 17 | 7902239404 |
| 18 | 29941371656 |
| 19 | 113447051497 |
| 20 | 429847830217 |
| 21 | 1628681887876 |
| 22 | 6171031956688 |
| 23 | 23381874459566 |
| 24 | 88593294803061 |
| 25 | 335677616363629 |