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 | -1 |
| 5 | 3 |
| 6 | 1 |
| 7 | 2 |
| 8 | -1 |
| 9 | 6 |
| 10 | 1 |
| 11 | -6 |
| 12 | 0 |
| 13 | 5 |
| 14 | 10 |
| 15 | 1 |
| 16 | 24 |
| 17 | 4 |
| 18 | -15 |
| 19 | 25 |
| 20 | 15 |
| 21 | 1 |
| 22 | -120 |
| 23 | -28 |
| 24 | 49 |
| 25 | -35 |
| 26 | 70 |
| 27 | 21 |
| 28 | 1 |
| 29 | 720 |
| 30 | 188 |
| 31 | -196 |
| 32 | 49 |
| 33 | 0 |
| 34 | 154 |
| 35 | 28 |
| 36 | 1 |
| 37 | -5040 |
| 38 | -1368 |
| 39 | 944 |
| 40 | 0 |
| 41 | -231 |
| 42 | 252 |
| 43 | 294 |
| 44 | 36 |
| 45 | 1 |
| 46 | 40320 |
| 47 | 11016 |
| 48 | -5340 |
| 49 | -820 |
| 50 | 1365 |
| 51 | -987 |
| 52 | 1050 |
| 53 | 510 |
| 54 | 45 |
| 55 | 1 |
| 56 | -362880 |
| 57 | -98208 |
| 58 | 34716 |
| 59 | 9020 |
| 60 | -7645 |
| 61 | 3003 |
| 62 | -1617 |
| 63 | 2970 |
| 64 | 825 |
| 65 | 55 |
| 66 | 1 |
| 67 | 3628800 |