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 | 0 |
| 3 | -2 |
| 4 | 0 |
| 5 | 4 |
| 6 | 6 |
| 7 | -8 |
| 8 | -24 |
| 9 | -2 |
| 10 | 48 |
| 11 | 76 |
| 12 | -42 |
| 13 | -224 |
| 14 | -144 |
| 15 | 406 |
| 16 | 744 |
| 17 | -332 |
| 18 | -2154 |
| 19 | -1400 |
| 20 | 4320 |
| 21 | 7702 |
| 22 | -2016 |
| 23 | -21428 |
| 24 | -17802 |
| 25 | 34216 |
| 26 | 76152 |
| 27 | -5210 |
| 28 | -195816 |
| 29 | -181916 |
| 30 | 300510 |
| 31 | 772432 |
| 32 | 53136 |
| 33 | -1851770 |
| 34 | -2055360 |
| 35 | 2388772 |
| 36 | 7515246 |
| 37 | 1755880 |
| 38 | -16586616 |
| 39 | -21354266 |
| 40 | 19195248 |
| 41 | 72641884 |
| 42 | 27527118 |