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 | 24 |
| 3 | 48 |
| 4 | 216 |
| 5 | 672 |
| 6 | 2208 |
| 7 | 6912 |
| 8 | 21408 |
| 9 | 65280 |
| 10 | 196992 |
| 11 | 589056 |
| 12 | 1748352 |
| 13 | 5156352 |
| 14 | 15124992 |
| 15 | 44156928 |
| 16 | 128383488 |
| 17 | 371908608 |
| 18 | 1073879040 |
| 19 | 3091820544 |
| 20 | 8878479360 |
| 21 | 25435250688 |
| 22 | 72710922240 |
| 23 | 207448571904 |
| 24 | 590798364672 |
| 25 | 1679765078016 |