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) |
|---|---|
| 1 | 1 |
| 2 | 12 |
| 3 | 60 |
| 4 | 1260 |
| 5 | 13860 |
| 6 | 180180 |
| 7 | 277200 |
| 8 | 900900 |
| 9 | 3628800 |
| 10 | 15315300 |
| 11 | 28828800 |
| 12 | 38880000 |
| 13 | 290990700 |
| 14 | 373248000 |
| 15 | 428828400 |
| 16 | 2036934900 |
| 17 | 2477260800 |
| 18 | 3632428800 |
| 19 | 6692786100 |
| 20 | 8147739600 |
| 21 | 13335840000 |
| 22 | 15682867200 |
| 23 | 15925248000 |
| 24 | 20956320000 |
| 25 | 46849502700 |
| 26 | 61751289600 |
| 27 | 65181916800 |
| 28 | 68976230400 |