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 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 5 |
| 7 | 9 |
| 8 | 22 |
| 9 | 60 |
| 10 | 164 |
| 11 | 494 |
| 12 | 1624 |
| 13 | 5602 |
| 14 | 20600 |
| 15 | 79813 |
| 16 | 323806 |
| 17 | 1371025 |
| 18 | 6034105 |
| 19 | 27513424 |
| 20 | 129641411 |
| 21 | 629862824 |
| 22 | 3149541908 |
| 23 | 16183100922 |
| 24 | 85328280263 |
| 25 | 461123500894 |
| 26 | 2551342936264 |
| 27 | 14438734591483 |
| 28 | 83506198920054 |
| 29 | 493163726073210 |
| 30 | 2971858162771887 |