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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | -2 |
| 5 | 1 |
| 6 | 0 |
| 7 | 9 |
| 8 | -6 |
| 9 | 1 |
| 10 | 9 |
| 11 | -36 |
| 12 | 42 |
| 13 | -12 |
| 14 | 1 |
| 15 | 0 |
| 16 | 225 |
| 17 | -300 |
| 18 | 130 |
| 19 | -20 |
| 20 | 1 |
| 21 | 225 |
| 22 | -1350 |
| 23 | 2475 |
| 24 | -1380 |
| 25 | 315 |
| 26 | -30 |
| 27 | 1 |
| 28 | 0 |
| 29 | 11025 |
| 30 | -22050 |
| 31 | 15435 |
| 32 | -4620 |
| 33 | 651 |
| 34 | -42 |
| 35 | 1 |
| 36 | 11025 |
| 37 | -88200 |
| 38 | 220500 |
| 39 | -182280 |
| 40 | 67830 |
| 41 | -12600 |
| 42 | 1204 |
| 43 | -56 |
| 44 | 1 |
| 45 | 0 |
| 46 | 893025 |
| 47 | -2381400 |
| 48 | 2302020 |
| 49 | -1020600 |
| 50 | 235494 |
| 51 | -29736 |
| 52 | 2052 |
| 53 | -72 |