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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 75 |
| 7 | 225 |
| 8 | 715 |
| 9 | 2347 |
| 10 | 7990 |
| 11 | 27908 |
| 12 | 99991 |
| 13 | 365587 |
| 14 | 1362310 |
| 15 | 5159208 |
| 16 | 19831101 |
| 17 | 77233517 |
| 18 | 304423574 |
| 19 | 1212962072 |
| 20 | 4881181036 |
| 21 | 19821471956 |
| 22 | 81165639197 |
| 23 | 334925706659 |
| 24 | 1391935877463 |
| 25 | 5823186349671 |
| 26 | 24511802558326 |
| 27 | 103772782048252 |
| 28 | 441696903185704 |