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 | -1 |
| 2 | 15 |
| 3 | -274 |
| 4 | 4910 |
| 5 | -88115 |
| 6 | 1581149 |
| 7 | -28372580 |
| 8 | 509125276 |
| 9 | -9135882405 |
| 10 | 163936757995 |
| 11 | -2941725761526 |
| 12 | 52787126949450 |
| 13 | -947226559328599 |
| 14 | 16997290940965305 |
| 15 | -305004010378046920 |
| 16 | 5473074895863879224 |
| 17 | -98210344115171779145 |