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 | 3 |
| 2 | -9 |
| 3 | 48 |
| 4 | -288 |
| 5 | 1917 |
| 6 | -13563 |
| 7 | 99927 |
| 8 | -758079 |
| 9 | 5879754 |
| 10 | -46401687 |
| 11 | 371336886 |
| 12 | -3005973612 |
| 13 | 24568135839 |
| 14 | -202441986099 |
| 15 | 1679863711851 |
| 16 | -14024710539684 |
| 17 | 117715876380531 |
| 18 | -992724682487382 |
| 19 | 8407187391492162 |
| 20 | -71467928398473984 |
| 21 | 609605247759545934 |
| 22 | -5215842747304421544 |
| 23 | 44752623977413097928 |
| 24 | -384969343166207926893 |