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 | 0 |
| 5 | -1 |
| 6 | 2 |
| 7 | -1 |
| 8 | 0 |
| 9 | 1 |
| 10 | 4 |
| 11 | -1 |
| 12 | -2 |
| 13 | -1 |
| 14 | 6 |
| 15 | 5 |
| 16 | 0 |
| 17 | -1 |
| 18 | -8 |
| 19 | -1 |
| 20 | -12 |
| 21 | 7 |
| 22 | 10 |
| 23 | -1 |
| 24 | 6 |
| 25 | 3 |
| 26 | 12 |
| 27 | -5 |
| 28 | -30 |
| 29 | -1 |
| 30 | -54 |
| 31 | -1 |
| 32 | 0 |
| 33 | 11 |
| 34 | 16 |
| 35 | 9 |
| 36 | 48 |
| 37 | -1 |
| 38 | 18 |
| 39 | 13 |
| 40 | 84 |
| 41 | -1 |
| 42 | -116 |
| 43 | -1 |
| 44 | -90 |
| 45 | -41 |
| 46 | 22 |
| 47 | -1 |
| 48 | -42 |
| 49 | 5 |
| 50 | -72 |
| 51 | 17 |
| 52 | -132 |
| 53 | -1 |
| 54 | 130 |
| 55 | 13 |
| 56 | 330 |
| 57 | 19 |
| 58 | 28 |
| 59 | -1 |
| 60 | 482 |
| 61 | -1 |
| 62 | 30 |
| 63 | -83 |
| 64 | 0 |
| 65 | 15 |
| 66 | -312 |
| 67 | -1 |
| 68 | -240 |
| 69 | 23 |
| 70 | -258 |