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 | 5 |
| 4 | 15 |
| 5 | 50 |
| 6 | 177 |
| 7 | 650 |
| 8 | 2449 |
| 9 | 9412 |
| 10 | 36761 |
| 11 | 145518 |
| 12 | 582556 |
| 13 | 2354557 |
| 14 | 9594898 |
| 15 | 39378259 |
| 16 | 162619316 |
| 17 | 675258452 |
| 18 | 2817643240 |
| 19 | 11808576745 |
| 20 | 49683880754 |
| 21 | 209786559004 |
| 22 | 888676860191 |
| 23 | 3775654643360 |
| 24 | 16084818268474 |
| 25 | 68694452578325 |
| 26 | 294053067958011 |