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 | 3 |
| 4 | 8 |
| 5 | 22 |
| 6 | 58 |
| 7 | 158 |
| 8 | 425 |
| 9 | 1161 |
| 10 | 3175 |
| 11 | 8751 |
| 12 | 24192 |
| 13 | 67239 |
| 14 | 187459 |
| 15 | 524579 |
| 16 | 1472086 |
| 17 | 4142639 |
| 18 | 11685501 |
| 19 | 33036492 |
| 20 | 93583873 |
| 21 | 265589158 |
| 22 | 754998424 |
| 23 | 2149588878 |
| 24 | 6128914829 |
| 25 | 17497927510 |
| 26 | 50017546412 |
| 27 | 143137957590 |
| 28 | 410062891934 |
| 29 | 1175925220607 |
| 30 | 3375322972597 |