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 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 54 |
| 6 | 210 |
| 7 | 841 |
| 8 | 3555 |
| 9 | 15402 |
| 10 | 68336 |
| 11 | 308206 |
| 12 | 1410175 |
| 13 | 6525500 |
| 14 | 30492934 |
| 15 | 143669529 |
| 16 | 681781043 |
| 17 | 3255653089 |
| 18 | 15632422715 |
| 19 | 75429279214 |
| 20 | 365556955492 |
| 21 | 1778608580060 |
| 22 | 8684658137204 |
| 23 | 42543288504844 |
| 24 | 209022441144144 |