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 | 0 |
| 4 | 1 |
| 5 | 44 |
| 6 | 7570 |
| 7 | 1975560 |
| 8 | 749649145 |
| 9 | 399035751464 |
| 10 | 289021136349036 |
| 11 | 277435664056527360 |
| 12 | 345023964977303838105 |
| 13 | 545099236551025860229460 |
| 14 | 1075595203804151695555622446 |