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 | 1 |
| 2 | 4 |
| 3 | 60 |
| 4 | 2960 |
| 5 | 454072 |
| 6 | 216266368 |
| 7 | 328381917376 |
| 8 | 1646431825247488 |
| 9 | 28147649085162289088 |
| 10 | 1682689316516069630268928 |
| 11 | 358405429181246295625283815424 |
| 12 | 275845379756819156941815068510302208 |