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 | 3 |
| 2 | -23 |
| 3 | -261 |
| 4 | 1425 |
| 5 | 37683 |
| 6 | -114951 |
| 7 | -7579989 |
| 8 | 3009057 |
| 9 | 1949504355 |
| 10 | 4981904649 |
| 11 | -608895679653 |
| 12 | -3580317475407 |
| 13 | 223074988560531 |
| 14 | 2158637035450905 |
| 15 | -93461683768765173 |
| 16 | -1316530828322729919 |
| 17 | 43902789604639578819 |
| 18 | 847901139421483812393 |