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 | 4 |
| 2 | -1 |
| 3 | 15 |
| 4 | -8 |
| 5 | 1 |
| 6 | 56 |
| 7 | -46 |
| 8 | 12 |
| 9 | -1 |
| 10 | 209 |
| 11 | -232 |
| 12 | 93 |
| 13 | -16 |
| 14 | 1 |
| 15 | 780 |
| 16 | -1091 |
| 17 | 592 |
| 18 | -156 |
| 19 | 20 |
| 20 | -1 |
| 21 | 2911 |
| 22 | -4912 |
| 23 | 3366 |
| 24 | -1200 |
| 25 | 235 |
| 26 | -24 |
| 27 | 1 |
| 28 | 10864 |
| 29 | -21468 |
| 30 | 17784 |
| 31 | -8010 |
| 32 | 2120 |
| 33 | -330 |
| 34 | 28 |
| 35 | -1 |
| 36 | 40545 |
| 37 | -91824 |
| 38 | 89238 |
| 39 | -48624 |
| 40 | 16255 |
| 41 | -3416 |
| 42 | 441 |
| 43 | -32 |
| 44 | 1 |
| 45 | 151316 |
| 46 | -386373 |
| 47 | 430992 |
| 48 | -275724 |
| 49 | 111524 |
| 50 | -29589 |
| 51 | 5152 |
| 52 | -568 |
| 53 | 36 |
| 54 | -1 |