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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 21 |
| 5 | 54 |
| 6 | 141 |
| 7 | 372 |
| 8 | 995 |
| 9 | 2697 |
| 10 | 7397 |
| 11 | 20502 |
| 12 | 57347 |
| 13 | 161658 |
| 14 | 458788 |
| 15 | 1309626 |
| 16 | 3757383 |
| 17 | 10828011 |
| 18 | 31326513 |
| 19 | 90945528 |