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 | -7 |
| 3 | -9 |
| 4 | 17 |
| 5 | 79 |
| 6 | 73 |
| 7 | -249 |
| 8 | -863 |
| 9 | -481 |
| 10 | 3353 |
| 11 | 9111 |
| 12 | 1457 |
| 13 | -42641 |
| 14 | -92567 |
| 15 | 28071 |
| 16 | 518977 |
| 17 | 897599 |
| 18 | -799687 |
| 19 | -6087369 |
| 20 | -8176303 |
| 21 | 14084239 |
| 22 | 69049993 |
| 23 | 67678791 |
| 24 | -209892383 |
| 25 | -758178721 |
| 26 | -466895527 |
| 27 | 2857102551 |
| 28 | 8048682737 |
| 29 | 1811852719 |
| 30 | -36619708247 |