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 | 127 |
| 8 | 323 |
| 9 | 834 |
| 10 | 2179 |
| 11 | 5743 |
| 12 | 15238 |
| 13 | 40637 |
| 14 | 108800 |
| 15 | 292200 |
| 16 | 786703 |
| 17 | 2122387 |
| 18 | 5735596 |
| 19 | 15522682 |
| 20 | 42064028 |
| 21 | 114117541 |
| 22 | 309918698 |
| 23 | 842489130 |
| 24 | 2292332265 |
| 25 | 6242655886 |