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 | 0 |
| 4 | -1 |
| 5 | 1 |
| 6 | 0 |
| 7 | -1 |
| 8 | 0 |
| 9 | 1 |
| 10 | 0 |
| 11 | -2 |
| 12 | -1 |
| 13 | 2 |
| 14 | 1 |
| 15 | 0 |
| 16 | -6 |
| 17 | -5 |
| 18 | 5 |
| 19 | 5 |
| 20 | 1 |
| 21 | 0 |
| 22 | -24 |
| 23 | -26 |
| 24 | 15 |
| 25 | 25 |
| 26 | 9 |
| 27 | 1 |
| 28 | 0 |
| 29 | -120 |
| 30 | -154 |
| 31 | 49 |
| 32 | 140 |
| 33 | 70 |
| 34 | 14 |
| 35 | 1 |
| 36 | 0 |
| 37 | -720 |
| 38 | -1044 |
| 39 | 140 |
| 40 | 889 |
| 41 | 560 |
| 42 | 154 |
| 43 | 20 |
| 44 | 1 |
| 45 | 0 |
| 46 | -5040 |
| 47 | -8028 |
| 48 | -64 |
| 49 | 6363 |
| 50 | 4809 |
| 51 | 1638 |
| 52 | 294 |
| 53 | 27 |
| 54 | 1 |
| 55 | 0 |
| 56 | -40320 |
| 57 | -69264 |
| 58 | -8540 |
| 59 | 50840 |
| 60 | 44835 |
| 61 | 17913 |
| 62 | 3990 |
| 63 | 510 |
| 64 | 35 |
| 65 | 1 |