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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 5 |
| 6 | 20 |
| 7 | 84 |
| 8 | 311 |
| 9 | 1165 |
| 10 | 4276 |
| 11 | 15802 |
| 12 | 58280 |
| 13 | 216070 |
| 14 | 803116 |
| 15 | 2997360 |
| 16 | 11221443 |
| 17 | 42147842 |
| 18 | 158749808 |
| 19 | 599513836 |
| 20 | 2269390757 |
| 21 | 8609258335 |
| 22 | 32725209938 |
| 23 | 124621150623 |
| 24 | 475367241264 |
| 25 | 1816100804241 |
| 26 | 6948222137523 |
| 27 | 26618662003342 |
| 28 | 102102765921611 |
| 29 | 392095326233619 |
| 30 | 1507357249572269 |
| 31 | 5800716924062537 |
| 32 | 22344021033377558 |