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 | -1 |
| 2 | -2 |
| 3 | -4 |
| 4 | -6 |
| 5 | -8 |
| 6 | -8 |
| 7 | 0 |
| 8 | 28 |
| 9 | 102 |
| 10 | 280 |
| 11 | 680 |
| 12 | 1544 |
| 13 | 3368 |
| 14 | 7152 |
| 15 | 14912 |
| 16 | 30706 |
| 17 | 62672 |
| 18 | 127124 |
| 19 | 256744 |
| 20 | 516952 |
| 21 | 1038672 |
| 22 | 2083864 |
| 23 | 4176576 |
| 24 | 8365080 |
| 25 | 16746150 |
| 26 | 33513608 |
| 27 | 67055456 |
| 28 | 134148160 |
| 29 | 268345208 |
| 30 | 536754288 |
| 31 | 1073591680 |
| 32 | 2147291036 |
| 33 | 4294721040 |
| 34 | 8589620784 |