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) |
|---|---|
| 1 | 1 |
| 2 | -127 |
| 3 | 2188 |
| 4 | -16511 |
| 5 | 78126 |
| 6 | -277876 |
| 7 | 823544 |
| 8 | -2113663 |
| 9 | 4785157 |
| 10 | -9922002 |
| 11 | 19487172 |
| 12 | -36126068 |
| 13 | 62748518 |
| 14 | -104590088 |
| 15 | 170939688 |
| 16 | -270549119 |
| 17 | 410338674 |
| 18 | -607714939 |
| 19 | 893871740 |
| 20 | -1289938386 |
| 21 | 1801914272 |
| 22 | -2474870844 |
| 23 | 3404825448 |
| 24 | -4624694644 |
| 25 | 6103593751 |
| 26 | -7969061786 |
| 27 | 10465138360 |
| 28 | -13597534984 |
| 29 | 17249876310 |