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 | 7 |
| 3 | -18 |
| 4 | 46 |
| 5 | -117 |
| 6 | 298 |
| 7 | -759 |
| 8 | 1933 |
| 9 | -4923 |
| 10 | 12538 |
| 11 | -31932 |
| 12 | 81325 |
| 13 | -207120 |
| 14 | 527497 |
| 15 | -1343439 |
| 16 | 3421495 |
| 17 | -8713926 |
| 18 | 22192786 |
| 19 | -56520993 |
| 20 | 143948698 |
| 21 | -366611175 |
| 22 | 933692041 |
| 23 | -2377943955 |
| 24 | 6056191126 |
| 25 | -15424018248 |
| 26 | 39282171577 |
| 27 | -100044552528 |
| 28 | 254795294881 |
| 29 | -648917313867 |