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 | 4 |
| 1 | 0 |
| 2 | 216 |
| 3 | 5104 |
| 4 | 13896 |
| 5 | 161568 |
| 6 | 1259712 |
| 7 | 2016496 |
| 8 | 2562624 |
| 9 | 14926248 |
| 10 | 58995000 |
| 11 | 34012224 |
| 12 | 150547032 |
| 13 | 471960000 |
| 14 | 119095488 |
| 15 | 1259712000 |
| 16 | 952763904 |
| 17 | 5159780352 |
| 18 | 3974344704 |
| 19 | 2176782336 |
| 20 | 10077696000 |
| 21 | 2985984000 |
| 22 | 36330467328 |
| 23 | 30723115968 |
| 24 | 23887872000 |
| 25 | 17414258688 |
| 26 | 72825163776 |
| 27 | 75686967000 |