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 | -1 |
| 4 | 1 |
| 5 | -2 |
| 6 | 1 |
| 7 | -4 |
| 8 | 2 |
| 9 | 1 |
| 10 | -6 |
| 11 | 6 |
| 12 | 1 |
| 13 | -9 |
| 14 | 18 |
| 15 | -6 |
| 16 | 1 |
| 17 | -12 |
| 18 | 36 |
| 19 | -24 |
| 20 | 1 |
| 21 | -16 |
| 22 | 72 |
| 23 | -96 |
| 24 | 24 |
| 25 | 1 |
| 26 | -20 |
| 27 | 120 |
| 28 | -240 |
| 29 | 120 |
| 30 | 1 |
| 31 | -25 |
| 32 | 200 |
| 33 | -600 |
| 34 | 600 |
| 35 | -120 |
| 36 | 1 |
| 37 | -30 |
| 38 | 300 |
| 39 | -1200 |
| 40 | 1800 |
| 41 | -720 |
| 42 | 1 |
| 43 | -36 |
| 44 | 450 |
| 45 | -2400 |
| 46 | 5400 |
| 47 | -4320 |
| 48 | 720 |
| 49 | 1 |
| 50 | -42 |
| 51 | 630 |
| 52 | -4200 |
| 53 | 12600 |
| 54 | -15120 |