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 | 0 |
| 1 | -1 |
| 2 | 0 |
| 3 | -128 |
| 4 | 2059 |
| 5 | -76066 |
| 6 | 2021086 |
| 7 | -60727431 |
| 8 | 1740361110 |
| 9 | -50782989034 |
| 10 | 1471652245341 |
| 11 | -42759682650188 |
| 12 | 1241158781898676 |
| 13 | -36040175501820901 |
| 14 | 1046363981321362852 |
| 15 | -30381064378888637148 |
| 16 | 882092032492683277335 |
| 17 | -25611107658594421205278 |
| 18 | 743603574761804566730466 |
| 19 | -21590121866471006254739195 |
| 20 | 626857059065125789349713930 |