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 | -5 |
| 5 | -1 |
| 6 | -6 |
| 7 | -1 |
| 8 | -16 |
| 9 | -9 |
| 10 | -8 |
| 11 | -1 |
| 12 | -14 |
| 13 | -1 |
| 14 | -12 |
| 15 | -10 |
| 16 | -35 |
| 17 | -1 |
| 18 | -22 |
| 19 | -1 |
| 20 | -22 |
| 21 | -14 |
| 22 | -14 |
| 23 | -1 |
| 24 | 10 |
| 25 | -13 |
| 26 | -18 |
| 27 | -56 |
| 28 | -38 |
| 29 | -1 |
| 30 | -17 |
| 31 | -1 |
| 32 | -31 |
| 33 | -16 |
| 34 | -20 |
| 35 | -16 |
| 36 | 42 |
| 37 | -1 |
| 38 | -24 |
| 39 | -20 |
| 40 | -2 |
| 41 | -1 |
| 42 | -33 |
| 43 | -1 |
| 44 | -46 |
| 45 | -54 |
| 46 | -30 |
| 47 | -1 |
| 48 | 243 |
| 49 | -21 |
| 50 | -46 |
| 51 | -22 |
| 52 | -62 |
| 53 | -1 |
| 54 | -10 |
| 55 | -18 |
| 56 | -26 |
| 57 | -26 |
| 58 | -32 |
| 59 | -1 |
| 60 | 140 |
| 61 | -1 |
| 62 | -38 |
| 63 | -86 |
| 64 | 160 |
| 65 | -22 |
| 66 | -41 |
| 67 | -1 |
| 68 | -70 |
| 69 | -32 |
| 70 | -53 |