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 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 21 |
| 6 | 51 |
| 7 | 128 |
| 8 | 327 |
| 9 | 858 |
| 10 | 2272 |
| 11 | 6146 |
| 12 | 16716 |
| 13 | 46246 |
| 14 | 128414 |
| 15 | 361493 |
| 16 | 1020506 |
| 17 | 2913060 |
| 18 | 8335405 |
| 19 | 24067930 |
| 20 | 69646035 |