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 | 60 |
| 2 | 1980 |
| 3 | 47520 |
| 4 | 926640 |
| 5 | 15567552 |
| 6 | 233513280 |
| 7 | 3202467840 |
| 8 | 40831464960 |
| 9 | 489977579520 |
| 10 | 5585744406528 |
| 11 | 60935393525760 |
| 12 | 639821632020480 |
| 13 | 6496650417438720 |
| 14 | 64038411257610240 |
| 15 | 614768748073058304 |
| 16 | 5763457013184921600 |
| 17 | 52888193768049868800 |
| 18 | 475993743912448819200 |