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 | 1 |
| 4 | 1 |
| 5 | -2 |
| 6 | 1 |
| 7 | 2 |
| 8 | -2 |
| 9 | 0 |
| 10 | 1 |
| 11 | 3 |
| 12 | 0 |
| 13 | -12 |
| 14 | 36 |
| 15 | 1 |
| 16 | 4 |
| 17 | 4 |
| 18 | -24 |
| 19 | 24 |
| 20 | 0 |
| 21 | 1 |
| 22 | 5 |
| 23 | 10 |
| 24 | -30 |
| 25 | -60 |
| 26 | 420 |
| 27 | -1800 |
| 28 | 1 |
| 29 | 6 |
| 30 | 18 |
| 31 | -24 |
| 32 | -216 |
| 33 | 720 |
| 34 | -720 |
| 35 | 0 |
| 36 | 1 |
| 37 | 7 |
| 38 | 28 |
| 39 | 0 |
| 40 | -420 |
| 41 | 420 |
| 42 | 5040 |
| 43 | -30240 |
| 44 | 176400 |
| 45 | 1 |
| 46 | 8 |
| 47 | 40 |
| 48 | 48 |
| 49 | -624 |
| 50 | -960 |
| 51 | 14400 |
| 52 | -40320 |
| 53 | 40320 |
| 54 | 0 |
| 55 | 1 |
| 56 | 9 |
| 57 | 54 |
| 58 | 126 |
| 59 | -756 |
| 60 | -3780 |
| 61 | 22680 |
| 62 | 22680 |
| 63 | -589680 |
| 64 | 3764880 |
| 65 | -28576800 |