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 | 0 |
| 1 | -2 |
| 2 | 14 |
| 3 | -58 |
| 4 | 198 |
| 5 | -602 |
| 6 | 1702 |
| 7 | -4570 |
| 8 | 11814 |
| 9 | -29658 |
| 10 | 72742 |
| 11 | -175066 |
| 12 | 414758 |
| 13 | -969690 |
| 14 | 2241574 |
| 15 | -5131226 |
| 16 | 11645990 |
| 17 | -26233818 |
| 18 | 58700838 |
| 19 | -130567130 |
| 20 | 288863270 |
| 21 | -635980762 |
| 22 | 1394062374 |
| 23 | -3043511258 |
| 24 | 6620165158 |