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) |
|---|---|
| 2 | 0 |
| 3 | 0 |
| 4 | 16 |
| 5 | 920 |
| 6 | 7800 |
| 7 | 36260 |
| 8 | 122080 |
| 9 | 334656 |
| 10 | 794640 |
| 11 | 1696200 |
| 12 | 3334320 |
| 13 | 6137560 |
| 14 | 10706696 |
| 15 | 17859660 |
| 16 | 28683200 |
| 17 | 44591680 |
| 18 | 67393440 |
| 19 | 99365136 |
| 20 | 143334480 |
| 21 | 202771800 |
| 22 | 281890840 |
| 23 | 385759220 |
| 24 | 520418976 |
| 25 | 693017600 |
| 26 | 911950000 |
| 27 | 1187011800 |
| 28 | 1529564400 |
| 29 | 1952712216 |
| 30 | 2471492520 |