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 | -6 |
| 3 | -36 |
| 4 | -1812 |
| 5 | -20748 |
| 6 | -773340 |
| 7 | -12237456 |
| 8 | -386587650 |
| 9 | -7368446268 |
| 10 | -211914644940 |
| 11 | -4517757977820 |
| 12 | -123221458979940 |
| 13 | -2814502962357420 |
| 14 | -74551748141034552 |
| 15 | -1778129476480366320 |
| 16 | -46377354051910716180 |
| 17 | -1137191336376638407704 |
| 18 | -29438532048777299115090 |
| 19 | -735051729258136807204140 |