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 | -4 |
| 2 | 17 |
| 3 | -75 |
| 4 | 340 |
| 5 | -1573 |
| 6 | 7393 |
| 7 | -35178 |
| 8 | 169035 |
| 9 | -818603 |
| 10 | 3989250 |
| 11 | -19538555 |
| 12 | 96084397 |
| 13 | -474052868 |
| 14 | 2344993157 |
| 15 | -11624422855 |
| 16 | 57722000172 |
| 17 | -287012948441 |
| 18 | 1428705217949 |
| 19 | -7118044107698 |
| 20 | 35489117143047 |
| 21 | -177036294035559 |
| 22 | 883588566571138 |
| 23 | -4411213326568599 |
| 24 | 22032317835916969 |