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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 14 |
| 6 | 44 |
| 7 | 152 |
| 8 | 566 |
| 9 | 2234 |
| 10 | 9228 |
| 11 | 39520 |
| 12 | 174271 |
| 13 | 787246 |
| 14 | 3628992 |
| 15 | 17019374 |
| 16 | 81011889 |
| 17 | 390633382 |
| 18 | 1905134695 |
| 19 | 9385453576 |
| 20 | 46653815395 |
| 21 | 233788460256 |
| 22 | 1180111379105 |
| 23 | 5996452414310 |
| 24 | 30653752894948 |