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 | 8 |
| 4 | 140 |
| 5 | 964 |
| 6 | 3920 |
| 7 | 11860 |
| 8 | 29708 |
| 9 | 65240 |
| 10 | 129984 |
| 11 | 240240 |
| 12 | 418220 |
| 13 | 693308 |
| 14 | 1103440 |
| 15 | 1696604 |
| 16 | 2532460 |
| 17 | 3684080 |
| 18 | 5239808 |
| 19 | 7305240 |
| 20 | 10005324 |
| 21 | 13486580 |
| 22 | 17919440 |
| 23 | 23500708 |
| 24 | 30456140 |
| 25 | 39043144 |
| 26 | 49553600 |
| 27 | 62316800 |