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 | 3 |
| 3 | 11 |
| 4 | 43 |
| 5 | 203 |
| 6 | 1123 |
| 7 | 7235 |
| 8 | 53171 |
| 9 | 439595 |
| 10 | 4037371 |
| 11 | 40787579 |
| 12 | 449500595 |
| 13 | 5366500163 |
| 14 | 68997666867 |
| 15 | 950475759899 |
| 16 | 13966170378907 |
| 17 | 218043973366091 |
| 18 | 3604426485899203 |
| 19 | 62894287709616755 |
| 20 | 1155219405655975763 |
| 21 | 22279674547003283003 |
| 22 | 450151092568978825707 |