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 | 3 |
| 3 | 7 |
| 4 | 16 |
| 5 | 39 |
| 6 | 98 |
| 7 | 252 |
| 8 | 659 |
| 9 | 1747 |
| 10 | 4682 |
| 11 | 12662 |
| 12 | 34505 |
| 13 | 94644 |
| 14 | 261069 |
| 15 | 723707 |
| 16 | 2014952 |
| 17 | 5631875 |
| 18 | 15796210 |
| 19 | 44444302 |
| 20 | 125405217 |
| 21 | 354765866 |
| 22 | 1006003375 |
| 23 | 2858939669 |
| 24 | 8141135778 |
| 25 | 23225997936 |
| 26 | 66376634429 |
| 27 | 190000938785 |