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 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 14 |
| 5 | 42 |
| 6 | 119 |
| 7 | 322 |
| 8 | 847 |
| 9 | 2180 |
| 10 | 5521 |
| 11 | 13804 |
| 12 | 34160 |
| 13 | 83818 |
| 14 | 204204 |
| 15 | 494494 |
| 16 | 1191227 |
| 17 | 2856666 |
| 18 | 6823334 |
| 19 | 16240714 |
| 20 | 38534657 |
| 21 | 91175154 |
| 22 | 215179125 |
| 23 | 506670394 |
| 24 | 1190534467 |
| 25 | 2792076392 |
| 26 | 6536567296 |
| 27 | 15278103876 |
| 28 | 35656587624 |
| 29 | 83101366684 |