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 | 0 |
| 2 | -2 |
| 3 | -6 |
| 4 | -82 |
| 5 | 530 |
| 6 | -2420 |
| 7 | 11718 |
| 8 | -77458 |
| 9 | 492834 |
| 10 | -1022532 |
| 11 | 3574714 |
| 12 | -39670180 |
| 13 | -172880396 |
| 14 | 3186538080 |
| 15 | -18558899356 |
| 16 | 150869023214 |
| 17 | -1286538054802 |
| 18 | 6854805868780 |
| 19 | -29675795883872 |
| 20 | 168219184363308 |
| 21 | -618102310289316 |
| 22 | -1450440026397056 |
| 23 | 26462673455854066 |