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 | 15 |
| 2 | 285 |
| 3 | 8475 |
| 4 | 378105 |
| 5 | 23823015 |
| 6 | 2018820885 |
| 7 | 221605991475 |
| 8 | 30596648805105 |
| 9 | 5189967817758015 |
| 10 | 1061021392126671885 |
| 11 | 257296819626005894475 |
| 12 | 73023341368629447792105 |
| 13 | 23978466652359211809453015 |