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 | 491 |
| 2 | 503 |
| 3 | 743 |
| 4 | 4294967783 |
| 5 | 115792089237316195423570985008687907853269984665640564039457584007913129640423 |