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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 0 |
| 7 | 2 |
| 8 | 1 |
| 9 | -10 |
| 10 | 39 |
| 11 | -58 |
| 12 | -166 |
| 13 | 1611 |
| 14 | -6311 |
| 15 | 10083 |
| 16 | 54195 |
| 17 | -565257 |
| 18 | 2727568 |
| 19 | -6102368 |
| 20 | -26464605 |
| 21 | 394614352 |
| 22 | -2515452801 |
| 23 | 8797315672 |
| 24 | 11441288836 |
| 25 | -458369484247 |
| 26 | 4097437715969 |
| 27 | -21769011878335 |
| 28 | 36715605929957 |
| 29 | 703213495381553 |
| 30 | -10042075731879152 |