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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 3 |
| 6 | 1 |
| 7 | 6 |
| 8 | 12 |
| 9 | 6 |
| 10 | 0 |
| 11 | 24 |
| 12 | 60 |
| 13 | 40 |
| 14 | 0 |
| 15 | -4 |
| 16 | 120 |
| 17 | 360 |
| 18 | 300 |
| 19 | 0 |
| 20 | -60 |
| 21 | 0 |
| 22 | 720 |
| 23 | 2520 |
| 24 | 2520 |
| 25 | 0 |
| 26 | -840 |
| 27 | 0 |
| 28 | 120 |
| 29 | 5040 |
| 30 | 20160 |
| 31 | 23520 |
| 32 | 0 |
| 33 | -11760 |
| 34 | 0 |
| 35 | 3360 |
| 36 | 0 |
| 37 | 40320 |
| 38 | 181440 |
| 39 | 241920 |
| 40 | 0 |
| 41 | -169344 |
| 42 | 0 |
| 43 | 80640 |
| 44 | 0 |
| 45 | -12096 |
| 46 | 362880 |
| 47 | 1814400 |
| 48 | 2721600 |
| 49 | 0 |
| 50 | -2540160 |
| 51 | 0 |
| 52 | 1814400 |
| 53 | 0 |
| 54 | -544320 |
| 55 | 0 |