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 | -6 |
| 2 | -9 |
| 3 | -36 |
| 4 | -189 |
| 5 | -1134 |
| 6 | -7371 |
| 7 | -50544 |
| 8 | -360126 |
| 9 | -2640924 |
| 10 | -19806930 |
| 11 | -151252920 |
| 12 | -1172210130 |
| 13 | -9197341020 |
| 14 | -72921775230 |
| 15 | -583374201840 |
| 16 | -4703454502335 |
| 17 | -38180983607190 |
| 18 | -311811366125385 |
| 19 | -2560135427134740 |
| 20 | -21121117273861605 |
| 21 | -175003543126281870 |
| 22 | -1455711290550435555 |