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 | 1 |
| 3 | -9 |
| 4 | -31 |
| 5 | 79 |
| 6 | 161 |
| 7 | -249 |
| 8 | -191 |
| 9 | -481 |
| 10 | -2879 |
| 11 | 9111 |
| 12 | 22049 |
| 13 | -42641 |
| 14 | -60319 |
| 15 | 28071 |
| 16 | -189311 |
| 17 | 897599 |
| 18 | 2643841 |
| 19 | -6087369 |
| 20 | -11130271 |
| 21 | 14084239 |
| 22 | 685601 |
| 23 | 67678791 |
| 24 | 274143169 |
| 25 | -758178721 |
| 26 | -1661999039 |
| 27 | 2857102551 |
| 28 | 3118415009 |
| 29 | 1811852719 |
| 30 | 22839485921 |
| 31 | -82298680089 |
| 32 | -214997290751 |