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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | -1 |
| 6 | 1 |
| 7 | -3 |
| 8 | -3 |
| 9 | -41 |
| 10 | 140 |
| 11 | -93456 |
| 12 | 280356252 |
| 13 | -471833669834248 |
| 14 | 40261350925439315783335171 |
| 15 | 20143180524957577201436416071451979623101429 |
| 16 | 9048277144756224572757714728840507662214586396123974675011643142128755383165 |