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 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 48 |
| 5 | 160 |
| 6 | 549 |
| 7 | 1924 |
| 8 | 6851 |
| 9 | 24700 |
| 10 | 89945 |
| 11 | 330239 |
| 12 | 1220884 |
| 13 | 4540128 |
| 14 | 16968958 |
| 15 | 63701573 |
| 16 | 240059998 |
| 17 | 907760348 |
| 18 | 3443048256 |
| 19 | 13094812968 |
| 20 | 49925646786 |
| 21 | 190772846082 |
| 22 | 730451716847 |
| 23 | 2802033270234 |
| 24 | 10767028435468 |
| 25 | 41438212118088 |
| 26 | 159711845145544 |
| 27 | 616393788920923 |
| 28 | 2381898673172602 |