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 | 2 |
| 2 | 6 |
| 3 | 33 |
| 4 | 280 |
| 5 | 3245 |
| 6 | 47376 |
| 7 | 828583 |
| 8 | 16817536 |
| 9 | 387783369 |
| 10 | 10003628800 |
| 11 | 285351587411 |
| 12 | 8916579449856 |
| 13 | 302881333613053 |
| 14 | 11112094003849216 |
| 15 | 437895198055227375 |
| 16 | 18446764996499439616 |
| 17 | 827240617573764860177 |
| 18 | 39346414477670243303424 |