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 | 7 |
| 2 | 21 |
| 3 | 35 |
| 4 | -7 |
| 5 | -273 |
| 6 | -1043 |
| 7 | -2261 |
| 8 | -1743 |
| 9 | 8855 |
| 10 | 47621 |
| 11 | 128499 |
| 12 | 180649 |
| 13 | -176897 |
| 14 | -1972131 |
| 15 | -6650245 |
| 16 | -12796063 |
| 17 | -4632537 |
| 18 | 71042293 |
| 19 | 316596931 |
| 20 | 769091673 |
| 21 | 860188175 |
| 22 | -1942889011 |
| 23 | -13792873269 |
| 24 | -41571269999 |
| 25 | -69734967113 |
| 26 | 12059021541 |
| 27 | 536380855955 |
| 28 | 2061110273033 |
| 29 | 4489775100447 |