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 | -2 |
| 2 | 2 |
| 3 | 4 |
| 4 | -14 |
| 5 | -52 |
| 6 | 284 |
| 7 | 1496 |
| 8 | -10958 |
| 9 | -74372 |
| 10 | 681652 |
| 11 | 5656616 |
| 12 | -62226116 |
| 13 | -610306712 |
| 14 | 7832965352 |
| 15 | 88645228304 |
| 16 | -1300254163918 |
| 17 | -16676932459172 |
| 18 | 275196007522436 |
| 19 | 3944890321174664 |
| 20 | -72330003541955564 |
| 21 | -1145979961718846152 |
| 22 | 23112838345877865752 |
| 23 | 401070175407076000624 |
| 24 | -8824400094691629670724 |