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 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 40 |
| 8 | 3192 |
| 9 | 119180 |
| 10 | 2119176 |
| 11 | 23636352 |
| 12 | 186506000 |
| 13 | 1131544008 |
| 14 | 5613017128 |
| 15 | 23670094984 |
| 16 | 87463182432 |
| 17 | 289367715488 |
| 18 | 872345119896 |
| 19 | 2427609997716 |
| 20 | 6305272324272 |