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 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 80 |
| 4 | 2690 |
| 5 | 155074 |
| 6 | 13658386 |
| 7 | 1706098008 |
| 8 | 286888266696 |
| 9 | 62485391828448 |
| 10 | 17112247116585744 |
| 11 | 5755236604915060944 |
| 12 | 2331975856351260982848 |
| 13 | 1120439648590390138640304 |
| 14 | 629855675998212293917375344 |
| 15 | 409557081242059531918330384896 |