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 | 2 |
| 5 | 1 |
| 6 | 2 |
| 7 | -3 |
| 8 | 3 |
| 9 | 1 |
| 10 | -6 |
| 11 | 8 |
| 12 | -6 |
| 13 | 4 |
| 14 | 1 |
| 15 | 24 |
| 16 | -30 |
| 17 | 20 |
| 18 | -10 |
| 19 | 5 |
| 20 | 1 |
| 21 | -120 |
| 22 | 144 |
| 23 | -90 |
| 24 | 40 |
| 25 | -15 |
| 26 | 6 |
| 27 | 1 |
| 28 | 720 |
| 29 | -840 |
| 30 | 504 |
| 31 | -210 |
| 32 | 70 |
| 33 | -21 |
| 34 | 7 |
| 35 | 1 |
| 36 | -5040 |
| 37 | 5760 |
| 38 | -3360 |
| 39 | 1344 |
| 40 | -420 |
| 41 | 112 |
| 42 | -28 |
| 43 | 8 |
| 44 | 1 |
| 45 | 40320 |
| 46 | -45360 |
| 47 | 25920 |
| 48 | -10080 |
| 49 | 3024 |
| 50 | -756 |
| 51 | 168 |
| 52 | -36 |
| 53 | 9 |
| 54 | 1 |
| 55 | -362880 |
| 56 | 403200 |
| 57 | -226800 |
| 58 | 86400 |
| 59 | -25200 |
| 60 | 6048 |
| 61 | -1260 |
| 62 | 240 |
| 63 | -45 |
| 64 | 10 |
| 65 | 1 |