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 | -3 |
| 3 | 46 |
| 4 | -1967 |
| 5 | 179351 |
| 6 | -29861639 |
| 7 | 8200834972 |
| 8 | -3456505906559 |
| 9 | 2118756407303197 |
| 10 | -1811589861406160699 |
| 11 | 2089746219541021377546 |
| 12 | -3164800617505630505525903 |
| 13 | 6151223064132377579849537011 |
| 14 | -15052264342298428131766095419839 |
| 15 | 45616620088948927404807879986431576 |
| 16 | -168785206495071742797011703980958673919 |