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 | 4 |
| 3 | 11 |
| 4 | 28 |
| 5 | 91 |
| 6 | 291 |
| 7 | 1004 |
| 8 | 3471 |
| 9 | 12350 |
| 10 | 44114 |
| 11 | 159519 |
| 12 | 579835 |
| 13 | 2121845 |
| 14 | 7800702 |
| 15 | 28813730 |
| 16 | 106844383 |
| 17 | 397647256 |
| 18 | 1484755972 |
| 19 | 5560561040 |
| 20 | 20881939915 |
| 21 | 78617991116 |
| 22 | 296678132514 |
| 23 | 1121988213996 |
| 24 | 4251702739831 |
| 25 | 16141719280994 |
| 26 | 61389611762126 |
| 27 | 233856524866209 |