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 | -2044 |
| 3 | -177139 |
| 4 | -4194288 |
| 5 | -48828093 |
| 6 | -362796992 |
| 7 | -1977326615 |
| 8 | -8589934336 |
| 9 | -31381059097 |
| 10 | -99999998976 |
| 11 | -285311668563 |
| 12 | -743008366592 |
| 13 | -1792160385845 |
| 14 | -4049565153280 |
| 15 | -8649755826607 |
| 16 | -17592185978880 |