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 | 6 |
| 4 | 23 |
| 5 | 61 |
| 6 | 171 |
| 7 | 497 |
| 8 | 1471 |
| 9 | 4389 |
| 10 | 13139 |
| 11 | 39385 |
| 12 | 118119 |
| 13 | 354317 |