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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 11 |
| 6 | 31 |
| 7 | 77 |
| 8 | 214 |
| 9 | 576 |
| 10 | 1592 |
| 11 | 4375 |
| 12 | 12183 |
| 13 | 33864 |
| 14 | 94741 |
| 15 | 265461 |
| 16 | 746372 |
| 17 | 2102692 |
| 18 | 5938630 |
| 19 | 16803610 |
| 20 | 47639902 |
| 21 | 135288198 |
| 22 | 384812502 |
| 23 | 1096141974 |
| 24 | 3126648842 |
| 25 | 8929715592 |
| 26 | 25533447030 |
| 27 | 73090099586 |
| 28 | 209438176485 |
| 29 | 600721031344 |
| 30 | 1724585494225 |