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 | 3 |
| 2 | 24 |
| 3 | 312 |
| 4 | 5616 |
| 5 | 129168 |
| 6 | 3616704 |
| 7 | 119351232 |
| 8 | 4535346816 |
| 9 | 195019913088 |
| 10 | 9360955828224 |
| 11 | 496130658895872 |
| 12 | 28775578215960576 |
| 13 | 1812861427605516288 |
| 14 | 123274577077175107584 |
| 15 | 8999044126633782853632 |
| 16 | 701925441877435062583296 |
| 17 | 58259811675827110194413568 |