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 | 2 |
| 2 | 9 |
| 3 | 74 |
| 4 | 1740 |
| 5 | 149572 |
| 6 | 48575680 |
| 7 | 56147642904 |
| 8 | 229149201466592 |
| 9 | 3333310913116926416 |
| 10 | 174695272793893644765312 |
| 11 | 33301710992572083379669646560 |
| 12 | 23278728241293538748514513208527104 |