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 | 0 |
| 2 | 0 |
| 3 | 5 |
| 4 | 205 |
| 5 | 11301 |
| 6 | 904580 |
| 7 | 101173251 |
| 8 | 15207243828 |
| 9 | 2975725761202 |
| 10 | 738628553556470 |
| 11 | 227636079973503479 |
| 12 | 85554823285296622543 |
| 13 | 38621481302086460057613 |
| 14 | 20669385794052533823555309 |
| 15 | 12966707189875262685801947906 |
| 16 | 9441485712482676603570079314728 |