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 | 9 |
| 2 | 584 |
| 3 | 70576 |
| 4 | 10909440 |
| 5 | 1913027840 |
| 6 | 361936623616 |
| 7 | 72033971859456 |
| 8 | 14864066521333760 |
| 9 | 3151356047929704448 |
| 10 | 682330743447507959808 |
| 11 | 150243739893975187718144 |
| 12 | 33540494675674022306381824 |