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 | 0 |
| 2 | 9 |
| 3 | 11 |
| 4 | 20 |
| 5 | 819 |
| 6 | 1221 |
| 7 | 2020 |
| 8 | 83629 |
| 9 | 124431 |
| 10 | 206040 |
| 11 | 8529239 |
| 12 | 12690841 |
| 13 | 21014040 |
| 14 | 869898849 |
| 15 | 1294341251 |
| 16 | 2143226060 |
| 17 | 88721153259 |
| 18 | 132010116861 |
| 19 | 218588044060 |
| 20 | 9048687733669 |
| 21 | 13463737578471 |
| 22 | 22293837268080 |
| 23 | 922877427680879 |