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 | 8 |
| 4 | 9 |
| 5 | -26 |
| 6 | -168 |
| 7 | 489 |
| 8 | 1041 |
| 9 | -5599 |
| 10 | 12 |
| 11 | 27103 |
| 12 | 23436 |
| 13 | -222912 |
| 14 | -435473 |
| 15 | 3177433 |
| 16 | 375569 |
| 17 | -24956018 |
| 18 | 6931209 |
| 19 | 181844002 |
| 20 | 57372644 |
| 21 | -2158209675 |
| 22 | 853739235 |
| 23 | 20642183588 |
| 24 | -25063980804 |
| 25 | -148768035501 |
| 26 | 224915906836 |
| 27 | 1322267927471 |
| 28 | -2337343745721 |
| 29 | -12604818831294 |