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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 0 |
| 4 | -5 |
| 5 | -3 |
| 6 | -73 |
| 7 | -11 |
| 8 | -2795 |
| 9 | -3055 |
| 10 | -58643 |
| 11 | -2561 |
| 12 | -4197973 |
| 13 | -614635 |
| 14 | -61269445 |
| 15 | -3871801 |
| 16 | -1495930487 |
| 17 | -23794993 |
| 18 | -26949145375 |
| 19 | -1677354925 |
| 20 | -1013112936505 |
| 21 | -30432904645 |
| 22 | -459074207581145 |
| 23 | -2099373575975 |
| 24 | -6497000065206625 |
| 25 | -11053607615333933 |
| 26 | -239235470859971731 |