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 | 2 |
| 2 | 3 |
| 3 | 5 |
| 4 | 13 |
| 5 | 7 |
| 6 | 23 |
| 7 | 21121 |
| 8 | 853 |
| 9 | 12157 |
| 10 | 213952189441 |
| 11 | 31 |
| 12 | 71427531245215711 |
| 13 | 17 |
| 14 | 163 |
| 15 | 68743 |
| 16 | 28031803 |
| 17 | 88717035481559 |
| 18 | 4549 |
| 19 | 38197 |
| 20 | 3835420378661 |
| 21 | 1573954557128833179852821957 |