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 | -1 |
| 2 | -1 |
| 3 | 0 |
| 4 | 2 |
| 5 | 1 |
| 6 | -1 |
| 7 | -4 |
| 8 | -2 |
| 9 | 4 |
| 10 | 12 |
| 11 | 4 |
| 12 | -20 |
| 13 | -39 |
| 14 | 3 |
| 15 | 92 |
| 16 | 118 |
| 17 | -84 |
| 18 | -388 |
| 19 | -308 |
| 20 | 596 |
| 21 | 1528 |
| 22 | 508 |
| 23 | -3292 |
| 24 | -5556 |
| 25 | 1154 |
| 26 | 16034 |
| 27 | 17940 |
| 28 | -18160 |
| 29 | -71243 |
| 30 | -45913 |
| 31 | 127124 |
| 32 | 290278 |
| 33 | 46128 |
| 34 | -710864 |
| 35 | -1067564 |
| 36 | 485108 |
| 37 | 3504680 |
| 38 | 3362756 |
| 39 | -4957812 |
| 40 | -15669148 |