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 | -2 |
| 2 | 1 |
| 3 | 5 |
| 4 | 4 |
| 5 | -53 |
| 6 | -177 |
| 7 | 282 |
| 8 | 5759 |
| 9 | 20355 |
| 10 | -83420 |
| 11 | -1420133 |
| 12 | -6245485 |
| 13 | 29035652 |
| 14 | 648899541 |
| 15 | 4034393367 |
| 16 | -10488623858 |
| 17 | -464971765297 |
| 18 | -4310935438663 |
| 19 | -3489419105786 |
| 20 | 446500913437911 |
| 21 | 6423072226704027 |
| 22 | 30987397708208720 |
| 23 | -462727554963927783 |
| 24 | -11862200720684515159 |