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 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 53 |
| 5 | 249 |
| 6 | 1223 |
| 7 | 6207 |
| 8 | 32296 |
| 9 | 171355 |
| 10 | 923583 |
| 11 | 5042840 |
| 12 | 27834231 |
| 13 | 155052721 |
| 14 | 870594423 |
| 15 | 4921968177 |
| 16 | 27995045409 |
| 17 | 160080985928 |
| 18 | 919731472614 |
| 19 | 5306779508096 |
| 20 | 30737417720495 |
| 21 | 178654274650097 |
| 22 | 1041678247875531 |
| 23 | 6091298104643577 |
| 24 | 35714017347725474 |