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 | 5 |
| 2 | -10 |
| 3 | 45 |
| 4 | -160 |
| 5 | 629 |
| 6 | -2590 |
| 7 | 11165 |
| 8 | -48910 |
| 9 | 217045 |
| 10 | -976258 |
| 11 | 4438925 |
| 12 | -20346440 |
| 13 | 93900245 |
| 14 | -435959830 |
| 15 | 2034505661 |
| 16 | -9536767660 |
| 17 | 44878791365 |
| 18 | -211927519090 |
| 19 | 1003867701485 |
| 20 | -4768372070128 |
| 21 | 22706531350485 |
| 22 | -108372079190350 |
| 23 | 518301258916445 |
| 24 | -2483526875847690 |
| 25 | 11920928955078629 |