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 | -1 |
| 2 | 7 |
| 3 | -76 |
| 4 | 1597 |
| 5 | -41776 |
| 6 | 1673167 |
| 7 | -74527636 |
| 8 | 4832747017 |
| 9 | -305644428256 |
| 10 | 30618856073947 |
| 11 | -2276081971574236 |
| 12 | 390042814538656957 |
| 13 | -20435946140834126176 |
| 14 | 10544180964356207226247 |
| 15 | 604793906292405974180324 |
| 16 | 688972694565220644332739217 |