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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 20 |
| 6 | 48 |
| 7 | 106 |
| 8 | 252 |
| 9 | 578 |
| 10 | 1372 |
| 11 | 3208 |
| 12 | 7584 |
| 13 | 17850 |
| 14 | 42102 |
| 15 | 99276 |
| 16 | 233716 |
| 17 | 550960 |
| 18 | 1295146 |
| 19 | 3050226 |
| 20 | 7161346 |
| 21 | 16846668 |
| 22 | 39511876 |
| 23 | 92845830 |