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 | 2 |
| 2 | 7 |
| 3 | 28 |
| 4 | 125 |
| 5 | 546 |
| 6 | 2527 |
| 7 | 11096 |
| 8 | 43633 |
| 9 | 186130 |
| 10 | 809831 |
| 11 | 3423432 |
| 12 | 14022373 |
| 13 | 58574894 |
| 14 | 250708291 |
| 15 | 1038612976 |
| 16 | 4353755777 |
| 17 | 18333324162 |
| 18 | 74663736859 |
| 19 | 311293807040 |
| 20 | 1286700247561 |
| 21 | 4917768055222 |
| 22 | 20458840039199 |
| 23 | 83985256000824 |