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 | 1 |
| 1 | 3 |
| 2 | 15 |
| 3 | 255 |
| 4 | 65535 |
| 5 | 4294967295 |
| 6 | 18446744073709551615 |
| 7 | 340282366920938463463374607431768211455 |
| 8 | 115792089237316195423570985008687907853269984665640564039457584007913129639935 |