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 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 5 |
| 7 | 15 |
| 8 | 53 |
| 9 | 213 |
| 10 | 961 |
| 11 | 4808 |
| 12 | 26405 |
| 13 | 157965 |
| 14 | 1022573 |
| 15 | 7122441 |
| 16 | 53118601 |
| 17 | 422362118 |
| 18 | 3566967917 |
| 19 | 31887812715 |
| 20 | 300848966213 |
| 21 | 2987359924149 |
| 22 | 31143724848889 |
| 23 | 340113005563268 |
| 24 | 3882897830626949 |
| 25 | 46254432194746377 |
| 26 | 573938743829923349 |
| 27 | 7406289665830324689 |