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 | -3 |
| 3 | 5 |
| 4 | 29 |
| 5 | -42 |
| 6 | -349 |
| 7 | 384 |
| 8 | 4705 |
| 9 | -3307 |
| 10 | -67530 |
| 11 | 19392 |
| 12 | 1006479 |
| 13 | 140594 |
| 14 | -15356600 |
| 15 | -8897336 |
| 16 | 237691865 |
| 17 | 246737931 |
| 18 | -3708348277 |
| 19 | -5655844305 |
| 20 | 58027927950 |
| 21 | 119178376245 |
| 22 | -906834380800 |
| 23 | -2396063640645 |
| 24 | 14094956420555 |
| 25 | 46748815762429 |
| 26 | -216921227330074 |