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 | 9 |
| 2 | 0 |
| 3 | 3 |
| 4 | 0 |
| 5 | 0 |
| 6 | -9 |
| 7 | 0 |
| 8 | 0 |
| 9 | 46 |
| 10 | 0 |
| 11 | 0 |
| 12 | -276 |
| 13 | 0 |
| 14 | 0 |
| 15 | 1827 |
| 16 | 0 |
| 17 | 0 |
| 18 | -12838 |
| 19 | 0 |
| 20 | 0 |
| 21 | 93885 |
| 22 | 0 |
| 23 | 0 |
| 24 | -706878 |
| 25 | 0 |
| 26 | 0 |
| 27 | 5440856 |
| 28 | 0 |
| 29 | 0 |
| 30 | -42608139 |
| 31 | 0 |
| 32 | 0 |
| 33 | 338345586 |
| 34 | 0 |
| 35 | 0 |
| 36 | -2717685006 |
| 37 | 0 |
| 38 | 0 |
| 39 | 22039352340 |
| 40 | 0 |
| 41 | 0 |
| 42 | -180191062062 |
| 43 | 0 |
| 44 | 0 |
| 45 | 1483568585389 |
| 46 | 0 |
| 47 | 0 |
| 48 | -12289222187157 |
| 49 | 0 |
| 50 | 0 |
| 51 | 102343255814052 |
| 52 | 0 |
| 53 | 0 |
| 54 | -856335797389803 |
| 55 | 0 |
| 56 | 0 |