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 | -11 |
| 3 | 47 |
| 4 | 241 |
| 5 | -2281 |
| 6 | -3779 |
| 7 | 104831 |
| 8 | -110207 |
| 9 | -4415281 |
| 10 | 16955269 |
| 11 | 161498831 |
| 12 | -1252782959 |
| 13 | -4376471737 |
| 14 | 73606867309 |
| 15 | 11876256767 |
| 16 | -3715460133887 |
| 17 | 9838677757343 |
| 18 | 160921055160469 |
| 19 | -957644184613393 |
| 20 | -5553047963695439 |
| 21 | 65231925087461879 |
| 22 | 102267746634093469 |