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 | 1 |
| 4 | 4 |
| 5 | 11 |
| 6 | 32 |
| 7 | 92 |
| 8 | 254 |
| 9 | 672 |
| 10 | 1778 |
| 11 | 4622 |
| 12 | 11938 |
| 13 | 30442 |
| 14 | 77396 |
| 15 | 194896 |
| 16 | 489620 |
| 17 | 1221134 |
| 18 | 3040194 |
| 19 | 7524933 |
| 20 | 18600478 |
| 21 | 45756483 |
| 22 | 112444948 |
| 23 | 275204606 |
| 24 | 673031750 |
| 25 | 1640168584 |
| 26 | 3994716336 |
| 27 | 9699476314 |