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 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | 24 |
| 5 | 30 |
| 6 | 180 |
| 7 | 70 |
| 8 | 1120 |
| 9 | 840 |
| 10 | 8400 |
| 11 | 630 |
| 12 | 83160 |
| 13 | 72072 |
| 14 | 1009008 |
| 15 | 1081080 |
| 16 | 192192 |
| 17 | 408408 |
| 18 | 7351344 |
| 19 | 2217072 |
| 20 | 8868288 |
| 21 | 203693490 |
| 22 | 71131060 |
| 23 | 74364290 |
| 24 | 4759314560 |
| 25 | 14872858000 |
| 26 | 77338861600 |
| 27 | 72282089880 |