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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 73 |
| 7 | 211 |
| 8 | 629 |
| 9 | 1912 |
| 10 | 5913 |
| 11 | 18531 |
| 12 | 58739 |
| 13 | 187963 |
| 14 | 606416 |
| 15 | 1970326 |
| 16 | 6441623 |
| 17 | 21175056 |
| 18 | 69946082 |
| 19 | 232054411 |
| 20 | 772886274 |
| 21 | 2583325555 |
| 22 | 8662455004 |
| 23 | 29132638803 |
| 24 | 98240253058 |
| 25 | 332105822674 |
| 26 | 1125273780474 |
| 27 | 3820859749502 |
| 28 | 12999287203624 |