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 | 6 |
| 2 | 120 |
| 3 | 2016 |
| 4 | 7140 |
| 5 | 61776 |
| 6 | 103740 |
| 7 | 738720 |
| 8 | 437580 |
| 9 | 1185030 |
| 10 | 4680270 |
| 11 | 4426800 |
| 12 | 2031120 |
| 13 | 6193440 |
| 14 | 4915680 |
| 15 | 30728880 |
| 16 | 2162160 |
| 17 | 48565440 |
| 18 | 134734320 |
| 19 | 286071240 |
| 20 | 163723560 |
| 21 | 376902240 |
| 22 | 536592420 |
| 23 | 137373600 |
| 24 | 76576500 |
| 25 | 391986000 |
| 26 | 214980480 |
| 27 | 103672800 |
| 28 | 1018606680 |
| 29 | 5401294080 |