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 | 4 |
| 3 | 52 |
| 4 | 206 |
| 5 | 734 |
| 6 | 4088 |
| 7 | 24801 |
| 8 | 130159 |
| 9 | 666434 |
| 10 | 3560105 |
| 11 | 19245643 |
| 12 | 102730864 |
| 13 | 546125038 |
| 14 | 2913904858 |
| 15 | 15571288925 |
| 16 | 83122383401 |
| 17 | 443489006259 |
| 18 | 2366877041892 |
| 19 | 12634189755271 |
| 20 | 67434790018093 |
| 21 | 359910312437155 |
| 22 | 1920940558913908 |