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) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | -5 |
| 4 | -3 |
| 5 | -93 |
| 6 | 95 |
| 7 | -793 |
| 8 | -211 |
| 9 | -5853 |
| 10 | 27003 |
| 11 | -215955 |
| 12 | 57459 |
| 13 | -3518265 |
| 14 | 3602027 |
| 15 | 16811055 |
| 16 | -4362627 |
| 17 | -1846943453 |
| 18 | 293601363 |
| 19 | -14911085359 |
| 20 | 4487888279 |
| 21 | 144251733709 |
| 22 | 245294787521 |
| 23 | -1936010885087 |
| 24 | 228009405371 |
| 25 | -11179552565305 |
| 26 | 63485965327535 |
| 27 | -48562641580527 |