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 | -21 |
| 3 | 33 |
| 4 | 4011 |
| 5 | 46617 |
| 6 | -1015581 |
| 7 | -48942687 |
| 8 | -234562629 |
| 9 | 46778432937 |
| 10 | 1609014050259 |
| 11 | -27879344558607 |
| 12 | -4096322988867669 |
| 13 | -82334747816721543 |
| 14 | 7943345993936306499 |
| 15 | 587663560859820510273 |