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 | 20 |
| 2 | 616 |
| 3 | 28160 |
| 4 | 1805056 |
| 5 | 154918400 |
| 6 | 17171485696 |
| 7 | 2389096202240 |
| 8 | 407776690241536 |
| 9 | 83793407533383680 |
| 10 | 20407552701432856576 |
| 11 | 5813146553630295326720 |
| 12 | 1914890082050142493474816 |
| 13 | 722310365729129175040655360 |
| 14 | 309331648183856602708764000256 |