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 | 3 |
| 2 | 7 |
| 3 | 31 |
| 4 | 127 |
| 5 | 983 |
| 6 | 122401 |
| 7 | 15231991 |
| 8 | 30341581 |
| 9 | 60439343 |
| 10 | 239818559 |
| 11 | 235883775871 |
| 12 | 935968272887 |
| 13 | 462162688688737 |
| 14 | 3592979567873032703 |
| 15 | 439785318101603999198591 |
| 16 | 432569613524779275706080077 |