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 | 6 |
| 3 | -3 |
| 4 | -21 |
| 5 | 24 |
| 6 | 195 |
| 7 | -111 |
| 8 | -3072 |
| 9 | -4053 |
| 10 | 57003 |
| 11 | 277854 |
| 12 | -697539 |
| 13 | -12261567 |
| 14 | -29861778 |
| 15 | 371727465 |
| 16 | 3511027599 |
| 17 | 2028432480 |
| 18 | -188521156857 |
| 19 | -1470389129931 |
| 20 | 1655487186864 |
| 21 | 121873222577823 |
| 22 | 915525253963023 |
| 23 | -2095901567014530 |
| 24 | -103715912230195863 |
| 25 | -836215492271268459 |