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 | -1 |
| 2 | -3 |
| 3 | -12 |
| 4 | -79 |
| 5 | -760 |
| 6 | -9561 |
| 7 | -147994 |
| 8 | -2716239 |
| 9 | -57632040 |
| 10 | -1387518625 |
| 11 | -37365406606 |
| 12 | -1112793904311 |
| 13 | -36312032900884 |
| 14 | -1288357188957489 |
| 15 | -49380149141206290 |
| 16 | -2033232328710195871 |
| 17 | -89506187915127440560 |
| 18 | -4194948681994077973377 |
| 19 | -208545134727411799745878 |