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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 5 |
| 5 | 141 |
| 6 | 2517 |
| 7 | 49835 |
| 8 | 1012858 |
| 9 | 24211837 |
| 10 | 721500293 |
| 11 | 22627459400 |
| 12 | 844130935667 |
| 13 | 34729870646917 |
| 14 | 1491483322755273 |
| 15 | 69890000837179156 |