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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 20160 |
| 9 | 60480 |
| 10 | 151200 |
| 11 | 332640 |
| 12 | 665280 |
| 13 | 1235520 |
| 14 | 2162160 |
| 15 | 3603600 |
| 16 | 5765760 |
| 17 | 8910720 |
| 18 | 13366080 |
| 19 | 19535040 |
| 20 | 27907200 |
| 21 | 39070080 |
| 22 | 53721360 |
| 23 | 72681840 |
| 24 | 96909120 |
| 25 | 127512000 |
| 26 | 165765600 |
| 27 | 213127200 |
| 28 | 271252800 |
| 29 | 342014400 |
| 30 | 427518000 |
| 31 | 530122320 |