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 | 4 |
| 2 | 13 |
| 3 | 49 |
| 4 | 154 |
| 5 | 577 |
| 6 | 1977 |
| 7 | 6962 |
| 8 | 24441 |
| 9 | 85803 |
| 10 | 300758 |
| 11 | 1056231 |
| 12 | 3705161 |
| 13 | 13002296 |
| 14 | 45626359 |
| 15 | 160104845 |
| 16 | 561810578 |
| 17 | 1971441799 |
| 18 | 6917860901 |
| 19 | 24275155066 |
| 20 | 85182802525 |
| 21 | 298910850927 |
| 22 | 1048893665520 |
| 23 | 3680622917741 |
| 24 | 12915496721997 |
| 25 | 45321151308320 |
| 26 | 159034280809195 |