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 | -1 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 4 |
| 7 | 6 |
| 8 | 19 |
| 9 | 38 |
| 10 | 67 |
| 11 | 127 |
| 12 | 234 |
| 13 | 419 |
| 14 | 745 |
| 15 | 1378 |
| 16 | 2678 |
| 17 | 5311 |
| 18 | 10470 |
| 19 | 20333 |