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 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 3 |
| 6 | -124 |
| 7 | -1306 |
| 8 | -10144 |
| 9 | -67723 |
| 10 | -363392 |
| 11 | -831672 |
| 12 | 16709824 |
| 13 | 386800759 |
| 14 | 5631873664 |
| 15 | 66256305994 |
| 16 | 619010054144 |
| 17 | 3201069236265 |
| 18 | -40479063835648 |
| 19 | -1775812586063860 |
| 20 | -39853546353553408 |
| 21 | -694055641682352469 |
| 22 | -9591063643658387456 |
| 23 | -84103588142498507346 |