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 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 15 |
| 5 | 49 |
| 6 | 255 |
| 7 | 2544 |
| 8 | 65535 |
| 9 | 6479346 |
| 10 | 4294967295 |
| 11 | 41981937869755 |
| 12 | 18446744073709551615 |
| 13 | 1762483107300123635910219390 |
| 14 | 340282366920938463463374607431768211455 |