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 | 2 |
| 1 | 4 |
| 2 | 12 |
| 3 | 64 |
| 4 | 700 |
| 5 | 17424 |
| 6 | 1053696 |
| 7 | 160579584 |
| 8 | 62856336636 |
| 9 | 63812936890000 |
| 10 | 168895157342195152 |
| 11 | 1169048914836855865344 |
| 12 | 21209591746609937928524800 |
| 13 | 1010490883477487017627972550656 |
| 14 | 126641164340871500483202065902080000 |
| 15 | 41817338589698457759723104703370865147904 |