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 | 1 |
| 3 | 5 |
| 4 | 41 |
| 5 | 437 |
| 6 | 5513 |
| 7 | 78477 |
| 8 | 1225865 |
| 9 | 20644021 |
| 10 | 370334137 |
| 11 | 7017055933 |
| 12 | 139562915193 |
| 13 | 2899946191077 |
| 14 | 62722686552841 |
| 15 | 1408033260333581 |
| 16 | 32729098457253417 |
| 17 | 786224322656857941 |
| 18 | 19486950945070339801 |
| 19 | 497649167866430159197 |
| 20 | 13078602790892074110937 |