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 | 7 |
| 1 | 9 |
| 2 | 21 |
| 3 | 261 |
| 4 | 65541 |
| 5 | 4294967301 |
| 6 | 18446744073709551621 |
| 7 | 340282366920938463463374607431768211461 |
| 8 | 115792089237316195423570985008687907853269984665640564039457584007913129639941 |