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 | 3 |
| 2 | -6 |
| 3 | -33 |
| 4 | 21 |
| 5 | 318 |
| 6 | 129 |
| 7 | -2733 |
| 8 | -3894 |
| 9 | 20703 |
| 10 | 55749 |
| 11 | -130578 |
| 12 | -632319 |
| 13 | 542883 |
| 14 | 6233754 |
| 15 | 1347807 |
| 16 | -54755979 |
| 17 | -66886242 |
| 18 | 425917569 |
| 19 | 1027893747 |
| 20 | -2805364374 |
| 21 | -12056408097 |
| 22 | 13191871269 |
| 23 | 121699544142 |
| 24 | 2972702721 |
| 25 | -1092323194557 |
| 26 | -1119077519046 |
| 27 | 8711831231967 |