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 | 5 |
| 4 | -11 |
| 5 | 6 |
| 6 | -61 |
| 7 | 211 |
| 8 | -240 |
| 9 | 90 |
| 10 | 1385 |
| 11 | -6551 |
| 12 | 11466 |
| 13 | -8820 |
| 14 | 2520 |
| 15 | -50521 |
| 16 | 303271 |
| 17 | -719580 |
| 18 | 844830 |
| 19 | -491400 |
| 20 | 113400 |
| 21 | 2702765 |
| 22 | -19665491 |
| 23 | 58998126 |
| 24 | -93511440 |
| 25 | 82661040 |
| 26 | -38669400 |
| 27 | 7484400 |
| 28 | -199360981 |
| 29 | 1704396331 |
| 30 | -6187282920 |
| 31 | 12372329970 |
| 32 | -14727913200 |
| 33 | 10443232800 |
| 34 | -4086482400 |
| 35 | 681080400 |