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 | -2 |
| 3 | 0 |
| 4 | 10 |
| 5 | 25 |
| 6 | -11 |
| 7 | -301 |
| 8 | -1040 |
| 9 | -60 |
| 10 | 17770 |
| 11 | 95359 |
| 12 | 146701 |
| 13 | -1513837 |
| 14 | -14210258 |
| 15 | -53101500 |
| 16 | 91834402 |
| 17 | 2739189073 |
| 18 | 19172894377 |
| 19 | 46384729811 |
| 20 | -498471972128 |
| 21 | -7229201676480 |
| 22 | -45007184571062 |
| 23 | -40076612769641 |
| 24 | 2435999270437801 |
| 25 | 30321258115161275 |
| 26 | 180120147363157438 |