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 | 4 |
| 2 | 24 |
| 3 | 198 |
| 4 | 2116 |
| 5 | 28052 |
| 6 | 446560 |
| 7 | 8325700 |
| 8 | 178284892 |
| 9 | 4317391240 |
| 10 | 116757568072 |
| 11 | 3489919886180 |
| 12 | 114304360656596 |
| 13 | 4072431454706374 |
| 14 | 156845310426959972 |
| 15 | 6494800764749659199 |
| 16 | 287796117221639178946 |
| 17 | 13590112496057829388516 |