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 | 0 |
| 2 | -1 |
| 3 | -3 |
| 4 | -10 |
| 5 | -45 |
| 6 | -271 |
| 7 | -2058 |
| 8 | -18775 |
| 9 | -199335 |
| 10 | -2410516 |
| 11 | -32683563 |
| 12 | -490870315 |
| 13 | -8087188200 |
| 14 | -144994236661 |
| 15 | -2810079139143 |
| 16 | -58536519252130 |
| 17 | -1304198088413265 |
| 18 | -30946462816602331 |
| 19 | -779104979758256298 |
| 20 | -20742005411397108595 |
| 21 | -582214473250983046155 |
| 22 | -17184302765073000634276 |