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 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 360 |
| 7 | 2520 |
| 8 | 20160 |
| 9 | 181440 |
| 10 | 907200 |
| 11 | 9979200 |
| 12 | 39916800 |
| 13 | 518918400 |
| 14 | 3632428800 |
| 15 | 18162144000 |
| 16 | 290594304000 |
| 17 | 4940103168000 |
| 18 | 44460928512000 |
| 19 | 844757641728000 |
| 20 | 4223788208640000 |
| 21 | 29566517460480000 |
| 22 | 325231692065280000 |
| 23 | 7480328917501440000 |
| 24 | 59842631340011520000 |