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 | 5 |
| 1 | -1 |
| 2 | -1 |
| 3 | -1 |
| 4 | -1 |
| 5 | 9 |
| 6 | -7 |
| 7 | -1 |
| 8 | -1 |
| 9 | -1 |
| 10 | 19 |
| 11 | -23 |
| 12 | 5 |
| 13 | -1 |
| 14 | -1 |
| 15 | 39 |
| 16 | -65 |
| 17 | 33 |
| 18 | -7 |
| 19 | -1 |
| 20 | 79 |
| 21 | -169 |
| 22 | 131 |
| 23 | -47 |
| 24 | 5 |
| 25 | 159 |
| 26 | -417 |
| 27 | 431 |
| 28 | -225 |
| 29 | 57 |
| 30 | 313 |
| 31 | -993 |
| 32 | 1279 |
| 33 | -881 |
| 34 | 339 |
| 35 | 569 |
| 36 | -2299 |
| 37 | 3551 |
| 38 | -3041 |
| 39 | 1559 |
| 40 | 799 |
| 41 | -5167 |
| 42 | 9401 |
| 43 | -9633 |
| 44 | 6159 |
| 45 | 39 |
| 46 | -11133 |
| 47 | 23969 |
| 48 | -28667 |
| 49 | 21951 |
| 50 | -6081 |
| 51 | -22305 |