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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 0 |
| 8 | 1 |
| 9 | 1 |
| 10 | 3 |
| 11 | 3 |
| 12 | 12 |
| 13 | 19 |
| 14 | 63 |
| 15 | 153 |
| 16 | 499 |
| 17 | 1473 |
| 18 | 4974 |
| 19 | 16296 |
| 20 | 56102 |
| 21 | 192899 |
| 22 | 674678 |
| 23 | 2381395 |
| 24 | 8468424 |