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 | 4 |
| 4 | -1 |
| 5 | -2 |
| 6 | 9 |
| 7 | -1 |
| 8 | -2 |
| 9 | -3 |
| 10 | 16 |
| 11 | -1 |
| 12 | -2 |
| 13 | -3 |
| 14 | -4 |
| 15 | 25 |
| 16 | -1 |
| 17 | -2 |
| 18 | -3 |
| 19 | -4 |
| 20 | -5 |
| 21 | 36 |
| 22 | -1 |
| 23 | -2 |
| 24 | -3 |
| 25 | -4 |
| 26 | -5 |
| 27 | -6 |
| 28 | 49 |
| 29 | -1 |
| 30 | -2 |
| 31 | -3 |
| 32 | -4 |
| 33 | -5 |
| 34 | -6 |
| 35 | -7 |
| 36 | 64 |