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 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 2 |
| 5 | 2 |
| 6 | 8 |
| 7 | 14 |
| 8 | 36 |
| 9 | 112 |
| 10 | 216 |
| 11 | 928 |
| 12 | 1440 |
| 13 | 8616 |
| 14 | 11520 |
| 15 | 87864 |
| 16 | 100800 |
| 17 | 997952 |
| 18 | 1008000 |
| 19 | 12427904 |
| 20 | 10886400 |
| 21 | 169435936 |
| 22 | 130636800 |
| 23 | 2501216992 |
| 24 | 1676505600 |
| 25 | 39837528576 |
| 26 | 23471078400 |
| 27 | 679494214656 |
| 28 | 348713164800 |
| 29 | 12370158205568 |
| 30 | 5579410636800 |
| 31 | 239109033342848 |