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 | -31 |
| 3 | -139 |
| 4 | 9871 |
| 5 | 324179 |
| 6 | -8225671 |
| 7 | -69685339 |
| 8 | 1674981058019 |
| 9 | 24279707153761 |
| 10 | -25107254122618741 |
| 11 | -1539511255447387949 |
| 12 | 181685125700898353671 |
| 13 | 368622611536873334281 |
| 14 | -538867967772767903436298889 |