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 | -1 |
| 2 | -1 |
| 3 | -2 |
| 4 | 4 |
| 5 | -3 |
| 6 | 3 |
| 7 | -6 |
| 8 | 75 |
| 9 | -152 |
| 10 | -4 |
| 11 | -21 |
| 12 | 1136 |
| 13 | -1118 |
| 14 | -1348 |
| 15 | -5846 |
| 16 | 20189 |
| 17 | -11851 |
| 18 | 17440 |
| 19 | -49133 |
| 20 | 119449 |
| 21 | -448210 |
| 22 | 72614 |
| 23 | 35800 |
| 24 | 6048178 |
| 25 | -6376555 |
| 26 | -5239650 |
| 27 | -25634644 |
| 28 | 52463464 |
| 29 | -20483411 |
| 30 | 155646867 |
| 31 | -229344925 |
| 32 | 664833536 |
| 33 | -2469711562 |
| 34 | 819287282 |