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 | 0 |
| 2 | 1 |
| 3 | 18 |
| 4 | 300 |
| 5 | 5400 |
| 6 | 108045 |
| 7 | 2408448 |
| 8 | 59521392 |
| 9 | 1620000000 |
| 10 | 48230748225 |
| 11 | 1560833556480 |
| 12 | 54591962772204 |
| 13 | 2053129541019648 |
| 14 | 82648417236328125 |
| 15 | 3546584706554265600 |
| 16 | 161642713497024891840 |
| 17 | 7799116552647941947392 |
| 18 | 397183826482614347896737 |