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 | 1 |
| 2 | 48 |
| 3 | 324 |
| 4 | 1792 |
| 5 | 3750 |
| 6 | 15552 |
| 7 | 19208 |
| 8 | 61440 |
| 9 | 85293 |
| 10 | 180000 |
| 11 | 175692 |
| 12 | 580608 |
| 13 | 399854 |
| 14 | 921984 |
| 15 | 1215000 |
| 16 | 2031616 |
| 17 | 1503378 |
| 18 | 4094064 |
| 19 | 2606420 |
| 20 | 6720000 |
| 21 | 6223392 |
| 22 | 8433216 |
| 23 | 6716184 |
| 24 | 19906560 |
| 25 | 12109375 |
| 26 | 19192992 |
| 27 | 21257640 |
| 28 | 34420736 |
| 29 | 21218430 |
| 30 | 58320000 |
| 31 | 29552672 |