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 | 66 |
| 2 | 2145 |
| 3 | 45760 |
| 4 | 720720 |
| 5 | 8936928 |
| 6 | 90858768 |
| 7 | 778789440 |
| 8 | 5743572120 |
| 9 | 37014131440 |
| 10 | 210980549208 |
| 11 | 1074082795968 |
| 12 | 4922879481520 |
| 13 | 20448884000160 |
| 14 | 77413632286320 |
| 15 | 268367258592576 |
| 16 | 855420636763836 |
| 17 | 2515943049305400 |
| 18 | 6848956078664700 |