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 | 2 |
| 2 | -2 |
| 3 | -10 |
| 4 | 6 |
| 5 | -26 |
| 6 | 38 |
| 7 | -90 |
| 8 | 166 |
| 9 | 678 |
| 10 | 1702 |
| 11 | -346 |
| 12 | 3750 |
| 13 | -4442 |
| 14 | 11942 |
| 15 | 44710 |
| 16 | 110246 |
| 17 | -20826 |
| 18 | 241318 |
| 19 | -282970 |
| 20 | 765606 |
| 21 | 2862758 |
| 22 | 7057062 |
| 23 | -1331546 |
| 24 | 15445670 |
| 25 | 49000102 |
| 26 | 116108966 |
| 27 | 250326694 |
| 28 | 518762150 |
| 29 | -18108762 |
| 30 | 1055633062 |