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 | 22 |
| 4 | 92 |
| 5 | 426 |
| 6 | 2150 |
| 7 | 11708 |
| 8 | 68282 |
| 9 | 423948 |
| 10 | 2788230 |
| 11 | 19341952 |
| 12 | 141003552 |
| 13 | 1076787624 |
| 14 | 8589843716 |
| 15 | 71404154928 |
| 16 | 617151121998 |
| 17 | 5535236798058 |
| 18 | 51426766394244 |
| 19 | 494145546973656 |
| 20 | 4903432458931118 |
| 21 | 50181840470551778 |
| 22 | 529009041574922566 |