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 | -1 |
| 3 | -3 |
| 4 | -2 |
| 5 | 35 |
| 6 | 233 |
| 7 | 406 |
| 8 | -6463 |
| 9 | -72951 |
| 10 | -234204 |
| 11 | 3454165 |
| 12 | 59129541 |
| 13 | 299098488 |
| 14 | -3983040037 |
| 15 | -98320221991 |
| 16 | -717243756890 |
| 17 | 8306677424447 |
| 18 | 290745526287213 |
| 19 | 2888789037885782 |
| 20 | -27716446593438731 |
| 21 | -1389236305462658939 |
| 22 | -18071746125863480076 |
| 23 | 133495439954224143065 |
| 24 | 10011730596035533451801 |