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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 7 |
| 6 | 16 |
| 7 | 45 |
| 8 | 111 |
| 9 | 318 |
| 10 | 881 |
| 11 | 2686 |
| 12 | 8033 |
| 13 | 25470 |
| 14 | 80480 |
| 15 | 263977 |
| 16 | 862865 |
| 17 | 2891344 |
| 18 | 9706757 |
| 19 | 33178076 |
| 20 | 113784968 |
| 21 | 395303480 |
| 22 | 1379160685 |
| 23 | 4859274472 |
| 24 | 17195407935 |
| 25 | 61310096228 |
| 26 | 219520467207 |
| 27 | 790749207801 |
| 28 | 2859542098634 |
| 29 | 10391610220375 |
| 30 | 37897965144166 |