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 | 3 |
| 5 | 4 |
| 6 | 12 |
| 7 | 24 |
| 8 | 74 |
| 9 | 193 |
| 10 | 635 |
| 11 | 1990 |
| 12 | 6933 |
| 13 | 24144 |
| 14 | 88203 |
| 15 | 326053 |
| 16 | 1234735 |
| 17 | 4732762 |
| 18 | 18403211 |
| 19 | 72282202 |
| 20 | 286705378 |