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 | 6 |
| 3 | 17 |
| 4 | 67 |
| 5 | 166 |
| 6 | 676 |
| 7 | 1373 |
| 8 | 4475 |
| 9 | 10446 |
| 10 | 30036 |
| 11 | 51032 |
| 12 | 196386 |
| 13 | 315302 |
| 14 | 737515 |
| 15 | 1654229 |
| 16 | 4227565 |
| 17 | 6301902 |
| 18 | 17975187 |
| 19 | 26010425 |
| 20 | 70085244 |
| 21 | 133337963 |