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 | 1 |
| 3 | 6 |
| 4 | 13 |
| 5 | 112 |
| 6 | 418 |
| 7 | 4025 |
| 8 | 23773 |
| 9 | 237256 |
| 10 | 2022526 |
| 11 | 20878803 |
| 12 | 236842838 |
| 13 | 2567676659 |
| 14 | 36410743437 |
| 15 | 419956671339 |
| 16 | 7116408372829 |
| 17 | 87937527652592 |
| 18 | 1724613303370022 |
| 19 | 22889017703271151 |
| 20 | 507452662263001722 |
| 21 | 7236316297556572973 |
| 22 | 178035555403835890935 |
| 23 | 2728137658918521763201 |