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 | 21 |
| 2 | 273 |
| 3 | 65793 |
| 4 | 4295032833 |
| 5 | 18446744078004518913 |
| 6 | 340282366920938463481821351505477763073 |
| 7 | 115792089237316195423570985008687907853610267032561502502920958615344897851393 |