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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 52 |
| 4 | 2027 |
| 5 | 70226 |
| 6 | 2280825 |
| 7 | 71112600 |
| 8 | 2155562551 |
| 9 | 64005323902 |
| 10 | 1870809923477 |
| 11 | 54006556365476 |
| 12 | 1543466751232275 |
| 13 | 43746473462661450 |
| 14 | 1231293799939647601 |
| 15 | 34451045198171912752 |
| 16 | 959005856055827234927 |
| 17 | 26576960554539062120726 |
| 18 | 733650711461388661963725 |