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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 18 |
| 6 | 40 |
| 7 | 94 |
| 8 | 228 |
| 9 | 579 |
| 10 | 1508 |
| 11 | 4092 |
| 12 | 11478 |
| 13 | 33337 |
| 14 | 100016 |
| 15 | 309916 |
| 16 | 990008 |
| 17 | 3257196 |
| 18 | 11021851 |
| 19 | 38314009 |
| 20 | 136657181 |
| 21 | 499570867 |
| 22 | 1869792499 |
| 23 | 7158070137 |
| 24 | 28003286261 |
| 25 | 111857491266 |
| 26 | 455852284867 |
| 27 | 1893959499405 |
| 28 | 8017007560487 |
| 29 | 34552315237016 |
| 30 | 151534813272661 |