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 | 3 |
| 2 | 10 |
| 3 | 21 |
| 4 | 73 |
| 5 | 190 |
| 6 | 510 |
| 7 | 1196 |
| 8 | 2895 |
| 9 | 6437 |
| 10 | 14281 |
| 11 | 29840 |
| 12 | 62405 |
| 13 | 124506 |
| 14 | 246383 |
| 15 | 473094 |
| 16 | 899000 |
| 17 | 1665763 |
| 18 | 3057894 |
| 19 | 5500889 |
| 20 | 9808150 |