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) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| 4 | -3 |
| 5 | 6 |
| 6 | -9 |
| 7 | 9 |
| 8 | 0 |
| 9 | -27 |
| 10 | 81 |
| 11 | -162 |
| 12 | 243 |
| 13 | -243 |
| 14 | 1 |
| 15 | 714 |
| 16 | -2067 |
| 17 | 3695 |
| 18 | -3519 |
| 19 | -4896 |
| 20 | 37621 |
| 21 | -129999 |
| 22 | 352716 |
| 23 | -836111 |
| 24 | 1802901 |
| 25 | -3605802 |
| 26 | 6760781 |
| 27 | -11961081 |
| 28 | 20058301 |
| 29 | -32017846 |
| 30 | 48916881 |
| 31 | -72174561 |
| 32 | 104394081 |
| 33 | -151428366 |
| 34 | 226511451 |
| 35 | -357639591 |
| 36 | 600805296 |