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 | 6 |
| 2 | -463 |
| 3 | -19340 |
| 4 | -259743 |
| 5 | -1936318 |
| 6 | -9960047 |
| 7 | -39530064 |
| 8 | -128452927 |
| 9 | -347066882 |
| 10 | -717524751 |
| 11 | -380620948 |
| 12 | 8681506849 |
| 13 | 86284511034 |
| 14 | 657562026065 |
| 15 | 4709118150568 |
| 16 | 33164211092865 |
| 17 | 232511926110710 |
| 18 | 1628215238620081 |